Patient interface

Abstract

A patient interface assembly including a headgear, a nasal interface and an electrical sensing arrangement. The nasal interface including a main portion between a first lateral portion and a second lateral portion, and at least one nasal delivery element extending from the main portion. The nasal interface is retained by the headgear with the first lateral portion and the second lateral portion held by the headgear. The electrical sensing arrangement being for detecting electrical activity of the patient to monitor a depth of anaesthesia of the patient. The electrical sensing arrangement including two or more electrical sensing elements distributed to one or both of the headgear and the nasal interface.

Description

PATIENT INTERFACETechnical Field

[0001] This disclosure generally relates to a patient interface. In particular, but not exclusively, various embodiments generally relate to a patient interface capable of delivering a high flow of gases to a patient and monitoring a depth of anaesthesia (or depth of sedation or level of consciousness) of the patient.Background

[0002] Medical procedures may involve procedural sedation or general anaesthesia, collectively known as anaesthetic procedures. In procedural sedation, a patient may have diminished respiratory function or risk thereof due to the anaesthetic agents and may become apnoeic. In general anaesthesia, patients will likely require mechanical ventilation if they become apnoeic. Pre-oxygenation of the patient prior to administration of anaesthetic agents is encouraged. During pre-oxygenation, also known as de-nitrogenation, the patient is provided with oxygen to saturate their body’s stores, including blood and lungs, to delay or avoid oxygen desaturation when the patient has diminished respiratory function or is apnoeic. Pre-oxygenation also reduces the patient’s blood and lung carbon dioxide levels, and nitrogen levels in the lungs due to replacement by oxygen.

[0003] Nasal High Flow (NHF) can be used in anaesthetic procedures to preoxygenate a patient, maintain adequate oxygenation and prevent desaturation, and in general anaesthesia when the patient becomes apnoeic, extend safe apnoea time during anaesthesia. NHF utilises a patient interface to deliver breathable gases, for example oxygen or oxygen enriched air or air, to a patient. NHF may also be used in other environments, such as wards, emergency departments and intensive care units (ICUs).

[0004] The patient interface used to deliver NHF to the patient typically includes a nasal interface. The nasal interface can include nasal delivery elements that are inserted into the patient’s nares to deliver the high flow of gases. The nasal interfaces may be non-sealing with the patient’s airways. Where there is more than one nasal delivery element, at least one nasal delivery element does not seal with the patient’s nare and where there is a single nasal delivery element, the nasal delivery element may seal with the nare while leaving the other nare unoccluded. NHF is a non-sealingtherapy or respiratory support that delivers high flow of gases, for example relatively high-volume flow rate to the patient through the nasal interface, which flow may be sufficient to meet or exceed the patient's inspiratory flow rate. NHF may be provided to spontaneously or non-spontaneously breathing patients.

[0005] During anaesthetic procedures, it is desirable to monitor the depth (or level) of anaesthesia (DoA) of a patient so that the patient is placed at an appropriate depth to, for example, withstand any stimulus arising from the ongoing medical procedure whilst minimizing risk of adverse events that increases with the DoA induced. Appropriate use of anaesthetics is useful to avoid waste.

[0006] However, conventionally, the NHF patient interface and the DoA monitors are separate and independent devices. Thus, having both the NHF patient interface and the DoA monitors on a patient’s face can be daunting to a patient. It can also be difficult for medical professionals to set up and / or use up area on the patient’s face that can hinder the medical procedure, for example during intubation and endoscopy procedures. Further, the NHF patient interface and the DoA monitors currently use different facial features as reference points for proper placement to achieve their functionalities, whereby respective placements may require overlapping or cause interference with each other.

[0007] It would be desirable to provide a solution to address one or more of the issues above.

[0008] The above discussion of the background to the disclosure is intended to facilitate an understanding of the disclosure. However, it is to be appreciated that the discussion is not an acknowledgement or admission that any aspect of the discussion was part of the common general knowledge of a skilled addressee as at the priority date of this application.Summary

[0009] According to an aspect, there is provided a patient interface assembly for a patient’s head, including: a headgear; a nasal interface including a main portion between a first lateral portion and a second lateral portion, and at least one nasal delivery element extending from the main portion,wherein the nasal interface is retained by the headgear with the first lateral portion and the second lateral portion held by the headgear; and an electrical sensing arrangement for detecting electrical activity of the patient to monitor a depth of anaesthesia of the patient, the electrical sensing arrangement including two or more electrical sensing elements distributed to one or both of the headgear and the nasal interface.

[0010] In one or more embodiments, each of the two or more electrical sensing elements is an electrode.

[0011] In one or more embodiments, the electrode is an electroencephalography electrode.

[0012] In one or more embodiments, each of the two or more electrical sensing elements is in the form of a cup, a disc, a patch, a pad or at least one needle.

[0013] In one or more embodiments, at least one of the two or more electrical sensing elements includes an adhesive surface and / or a frictional surface.

[0014] In one or more embodiments, the adhesive surface and / or frictional surface surrounds at least one of the two or more electrical sensing elements.

[0015] In one or more embodiments, the adhesive surface and / or frictional surface comprises part of one or both of the headgear and the nasal interface.

[0016] In one or more embodiments, the electrical sensing arrangement includes three or more electrical sensing elements.

[0017] In one or more embodiments, at least one of the two or more electrical sensing elements is fixedly attached to one or both of the headgear and the nasal interface.

[0018] In one or more embodiments, the at least one of the two or more electrical sensing elements is embedded in one or both of the headgear and the nasal interface.

[0019] In one or more embodiments, at least one of the two or more electrical sensing elements is movably attached to one or both of the headgear and the nasal interface in a manner so as to be translatable between different positions thereof.

[0020] In one or more embodiments, when the at least one of the two or more electrical sensing elements is movably attached to the headgear, the at least one of the two or more electrical sensing elements is attached to a slide attachment, the slide attachment including a slide channel through which a strap of the headgear is fitted such that the slide attachment is slidable relative to the strap of the headgear for moving said electrical sensing element along the strap of the headgear.

[0021] In one or more embodiments, the at least one of the two or more electrical sensing elements is removably attached thereto.

[0022] In one or more embodiments, at least one of the two or more electrical sensing elements is removably attached to one or both of the headgear and the nasal interface.

[0023] In one or more embodiments, the headgear includes a network of straps, wherein the network of straps includes a pair of nodes respectively at two opposite lateral portions of the headgear corresponding to left and right portions of the headgear with the nasal interface being at an anterior position of the headgear.

[0024] In one or more embodiments, the network of straps includes a first strap segment extending from a first node of the pair of nodes to the first lateral portion of the nasal interface and a second strap segment extending from a second node of the pair of nodes to the second lateral portion of the nasal interface.

[0025] In one or more embodiments, the patient interface assembly further includes at least one non-electrical sensing element attached to one or both of the headgear and the nasal interface, wherein the at least one non-electrical sensing element includes one of a photosensing element, an optical sensing element, or a thermosensing element.

[0026] In one or more embodiments, the at least one nasal delivery element is a nasal prong.

[0027] In one or more embodiments, the nasal interface includes two nasal prongs.

[0028] In one or more embodiments, the two nasal prongs are of different dimensions.

[0029] In one or more embodiments, the two nasal prongs are of a same dimension.

[0030] In one or more embodiments, the headgear is conformable to the patient’s head for wearing on the patient’s head, wherein, when the headgear is worn on the patient’s head, the nasal interface is retained to bear against a nose of the patient along a first vector (i.e. an interface vector) to maintain the nasal interface in a position and an orientation for delivering consistent gases flow into the nose of the patient, and at least one of the two or more electrical sensing elements of the electrical sensing arrangement is retained to bear against a corresponding position of the patient’s head along a second vector (i.e. an electrode vector) to maximise contact with the corresponding position of the patient’s head.

[0031] In one or more embodiments, the first vector forms an angle with a transverse plane of the patient’s head and is directed towards a coronal plane of the patient’s head, wherein the angle is between 0° and 90°.

[0032] In one or more embodiments, the second vector is directed substantially perpendicular towards the corresponding position of the patient’s head.

[0033] In one or more embodiments, the headgear is resilient and is capable of returning to a contracted state for conforming the headgear to the patient’s head after being widened to an expanded state.

[0034] In one or more embodiments, the headgear includes elastic material stretchable to conform the headgear to the patient’s head.

[0035] In one or more embodiments, the headgear includes an adjustable arrangement to tighten the headgear for conforming to the patient’s head.

[0036] In one or more embodiments, the adjustable arrangement includes one or more or a combination of a ring, a slide, a hook, a buckle, or a strap adjuster for adjusting one or more straps of the headgear.

[0037] In one or more embodiments, the headgear includes a head strap portion that forms a continuous loop with the nasal interface.

[0038] In one or more embodiments, the head strap portion extends from the first lateral portion of the nasal interface to the second lateral portion of the nasal interface.

[0039] In one or more embodiments, the two or more electrical sensing elements of the electrical sensing arrangement are distributed along the continuous loop.

[0040] In one or more embodiments, a distribution of the two or more electrical sensing elements from the first lateral portion of the nasal interface to a mid-point of the head strap portion is symmetrical with a distribution of the two or more electrical sensing elements from the second lateral portion of the nasal interface to the mid-point of the head strap portion.

[0041] In one or more embodiments, each of the two or more electrical sensing elements is disposed along the continuous loop at a corresponding predetermined distance from a mid-point of the main portion of the nasal interface.

[0042] In one or more embodiments, the continuous loop formed by the head strap portion of the headgear and the nasal interface is configured to loop across a top region of the patient’s head.

[0043] In one or more embodiments, the headgear includes a nasal strap portion for wearing over a nose bridge of the patient.

[0044] In one or more embodiments, the nasal strap portion extends from the first lateral portion of the nasal interface to the second lateral portion of the nasal interface.

[0045] In one or more embodiments, the nasal strap portion is of a predetermined length so as to maintain the nasal interface in place when worn.

[0046] In one or more embodiments, the nasal strap portion is configured to apply a countering force to resist a load on one or more sides of the nasal interface.

[0047] In one or more embodiments, at least one of the two or more electrical sensing elements of the electrical sensing arrangement is disposed at the nasal strap portion of the headgear.

[0048] In one or more embodiments, a disposition of the at least one of the two or more electrical sensing elements and the nasal strap portion is configured to apply a countering force to resist a load on one or more sides of the nasal interface.

[0049] In one or more embodiments, the headgear includes a forehead strap portion for wearing across a forehead of the patient.

[0050] In one or more embodiments, at least one of the two or more electrical sensing elements of the electrical sensing arrangement is disposed at the forehead strap portion of the headgear.

[0051] In one or more embodiments, the patient interface assembly includes at least one electrical sensing element disposed at the first lateral portion of the nasal interface and at least one further electrical sensing element disposed at the second lateral portion of the nasal interface.

[0052] In one or more embodiments, the patient interface assembly includes two electrical sensing elements disposed side-by-side lengthwise at the first lateral portion of the nasal interface and / or two electrical sensing elements disposed side-by-side lengthwise at the second lateral portion of the nasal interface.

[0053] In one or more embodiments, the patient interface assembly includes two electrical sensing elements disposed at the first lateral portion of the nasal interface and side-by-side along a direction transverse to a length of the first lateral portion, and / or two electrical sensing elements disposed in at the second lateral portion of the nasal interface and side-by-side along a direction transverse to a length of the second lateral portion.

[0054] In one or more embodiments, the nasal interface includes at least one gases flow port disposed at one of (i) the main portion or (ii) the first lateral portion and / or the second lateral portion of the nasal interface, the at least one gases flow port being for receiving a gases flow, wherein the at least one gases flow port is in fluid communication with the at least one nasal delivery element.

[0055] In one or more embodiments, when the at least one gases flow port is disposed at the first lateral portion, the main portion includes a manifold, the first lateral portion includes a gases delivery side member extending from a corresponding side of the manifold, and the second lateral portion includes a non-delivery side member extending from a corresponding opposite side of the manifold, wherein an end of the gases delivery side member distal from the manifold includes a delivery inlet serving as the at least one gases flow port, wherein the at least one nasal delivery element extends from the manifold.

[0056] In one or more embodiments, when the at least one gases flow port is disposed at the second lateral portion, the main portion includes a manifold, the second lateral portion includes a gases delivery side member extending from a corresponding side of the manifold, and the first lateral portion includes a non-delivery side member extending from a corresponding opposite side of the manifold, wherein an end of the gases delivery side member distal from the manifold includes a delivery inlet serving as the at least one gases flow port, wherein the at least one nasal delivery element extends from the manifold.

[0057] In one or more embodiments, the gases delivery side member includes a collapsible portion operable to change between a normally open configuration and a collapsed configuration.

[0058] In one or more embodiments, the collapsible portion changes from the normally open configuration to the collapsed configuration upon application of a collapsing force to the collapsible portion.

[0059] In one or more embodiments, the patient interface assembly further includes a gas path connector connected to the delivery inlet.

[0060] In one or more embodiments, when the at least one gases flow port is disposed at the main portion, the at least one gases flow port is an opening in the main portion providing direct fluid access into a flow passage of the at least one nasal delivery element.

[0061] In one or more embodiments, the nasal interface includes a face mount part with an upper portion serving as the main portion from which the at least one nasal delivery element extends, and the at least one gases flow port is an aperture in the upper portion opening into the flow passage of the at least one nasal delivery element extending from the upper portion of the face mount part.

[0062] In one or more embodiments, the face mount part includes a face contacting portion, wherein upper portion and the face contacting portion are at an angle to one another.

[0063] In one or more embodiments, the face mount part includes an auxiliary portion extending from the upper portion to the face contacting portion to form a recess capable of receiving a gases flow manifold part.

[0064] In one or more embodiments, the aperture in the upper portion is located along a segment of the upper portion forming the recess with the face contacting portion and the auxiliary portion.

[0065] In one or more embodiments, the recess includes two lateral openings for lateral insertion of the gases flow manifold part into the face mount part.

[0066] In one or more embodiments, the gases flow manifold part is at an end of a gas conduit, wherein an end of the gases flow manifold part distal from the gas conduit is closed and the gases flow manifold part has an opening along a side of the gases flow manifold part, whereby the opening of the gases flow manifold part is capable of being aligned to the aperture of the upper portion of the face mount part when inserted into the face mount part via any one of the two lateral openings of the recess.

[0067] In one or more embodiments, electrical wirings of the two or more electrical sensing elements of the electrical sensing arrangement are routed to the nasal interface.

[0068] In one or more embodiments, the nasal interface includes electrical connection points for the electrical wirings of the two or more electrical sensing elements.

[0069] In one or more embodiments, the at least one gases flow port and the electrical connection points are integrated together as a single connector for connecting to the gases flow delivery line and an electrical network for communication signals from the two or more electrical sensing elements.

[0070] In one or more embodiments, the electrical connection points are integrated with the delivery inlet of the gases delivery side member.

[0071] In one or more embodiments, the electrical connection points are integrated with the aperture in the upper portion of the face mount part.

[0072] According to an aspect, there is provided a patient interface assembly including: a headgear including a head strap portion for wearing around a back of a patient’s head; a nasal interface includinga main portion, and at least one nasal delivery element extending from the main portion, wherein the nasal interface is held by the headgear to form a continuous loop; and an electrical sensing arrangement for detecting electrical activity of a patient to monitor a depth of anaesthesia of the patient, the electrical sensing arrangement including two or more electrical sensing elements distributed along the continuous loop.

[0073] In one or more embodiments, wherein the main portion of the nasal interface is between a first lateral portion and a second lateral portion of the nasal interface, wherein the head strap portion of the headgear extends from the first lateral portion of the nasal interface to the second lateral portion of the nasal interface.

[0074] In one or more embodiments, a distribution of the two or more electrical sensing elements from the first lateral portion of the nasal interface to a mid-point of the head strap portion is symmetrical with a distribution of the two or more electrical sensing elements from the second lateral portion of the nasal interface to the mid-point of the head strap portion.

[0075] In one or more embodiments, each of the two or more electrical sensing elements is disposed along the continuous loop at a corresponding predetermined distance from a mid-point of the main portion of the nasal interface.

[0076] In one or more embodiments, the continuous loop formed by the head strap portion of the headgear and the nasal interface is configured to loop across a top region of the patient’s head.

[0077] In one or more embodiments, wherein the head strap portion of the headgear is conformable to the patient’s head for wearing on the patient’s head, wherein, when the headgear is worn on the patient’s head, the nasal interface is retained to bear against a nose of the user along a first vector to maintain the nasal interface in a position and an orientation for delivering consistent gases flow into the nose of the patient, and at least one of the two or more electrical sensing elements of the electrical sensing arrangement is retained to bear against a corresponding position of the patient’s head along a second vector to maximise contact with the corresponding position of the patient’s head.

[0078] In one or more embodiments, the first vector forms an angle with a transverse plane of the patient’s head and is directed towards a coronal plane of the patient’s head, wherein the angle is between 0° and 90°.

[0079] In one or more embodiments, the second vector is directed substantially perpendicular towards the corresponding position of the patient’s head.

[0080] In one or more embodiments, the head strap portion of the headgear is resilient and is capable of returning to a contracted state for conforming the head strap portion of the headgear to the patient’s head after being widened to an expanded state.

[0081] In one or more embodiments, the head strap portion of the headgear includes elastic material stretchable to conform the head strap portion of the headgear to the patient’s head.

[0082] In one or more embodiments, the head strap portion of the headgear includes an adjustable arrangement to tighten the head strap portion of the headgear for conforming to the patient’s head.

[0083] In one or more embodiments, the adjustable arrangement includes one or more or a combination of a ring, a slide, a hook, a buckle, or a strap adjuster for adjusting the head strap portion of the headgear.

[0084] In one or more embodiments, at least one of the two or more electrical sensing elements is fixedly attached to one or both of the head strap portion of the headgear and the nasal interface.

[0085] In one or more embodiments, the at least one of the two or more electrical sensing elements is embedded in one or both of the head strap portion of the headgear and the nasal interface.

[0086] In one or more embodiments, at least one of the two or more electrical sensing elements is movably attached to one or both of the head strap portion of the headgear and the nasal interface in a manner so as to be translatable between different positions thereof.

[0087] In one or more embodiments, when the at least one of the two or more electrical sensing elements is movably attached to the head strap portion of the headgear, the at least one of the two or more electrical sensing elements is attached to a slide attachment, the slide attachment including a slide channel through which the head strap portion of the headgear is fitted such that the slide attachment is slidable relative to the head strap portion of the headgear for moving said electrical sensing element along the head strap portion of the headgear.

[0088] In one or more embodiments, the at least one of the two or more electrical sensing elements is removably attached thereto.

[0089] In one or more embodiments, at least one of the two or more electrical sensing elements is removably attached to one or both of the head strap portion of the headgear and the nasal interface.

[0090] According to an aspect, there is provided a patient interface assembly for a patient’s head including: a headgear including a nasal strap portion for wearing over a nose bridge of the patient; a nasal interface including a main portion, and at least one nasal delivery element extending from the main portion, wherein the nasal interface is held by the headgear; and an electrical sensing arrangement for detecting electrical activity of the patient to monitor a depth of anaesthesia of the patient, the electrical sensing arrangement including two or more electrical sensing elements distributed to one or both of the nasal strap portion of the headgear and the nasal interface.

[0091] In one or more embodiments, the main portion of the nasal interface is between a first lateral portion and a second lateral portion of the nasal interface, wherein the nasal strap portion of the headgear extends from the first lateral portion of the nasal interface to the second lateral portion of the nasal interface.

[0092] In one or more embodiments, the nasal strap portion is of a predetermined length so as to maintain the nasal interface in place when worn.

[0093] In one or more embodiments, the nasal strap portion is configured to apply a countering force to resist a load on one or more sides of the nasal interface.

[0094] In one or more embodiments, at least one of the two or more electrical sensing elements of the electrical sensing arrangement is disposed at the nasal strap portion of the headgear.

[0095] In one or more embodiments, a disposition of the at least one of the two or more electrical sensing elements and the nasal strap portion is configured to apply a countering force to resist a load on one or more sides of the nasal interface.

[0096] In one or more embodiments, the nasal strap portion of the headgear is conformable to the nose bridge of the patient for wearing over the nose bridge of the patient, wherein, when the headgear is worn, the nasal interface is retained to bear against a nose of the patient along a first vector to maintain the nasal interface in a position and an orientation for delivering consistent gases flow into the nose of thepatient, and at least one of the two or more electrical sensing elements of the electrical sensing arrangement is retained to bear against a corresponding position of the nose bridge of the patient along a second vector to maximise contact with the corresponding position of nose bridge of the patient.

[0097] In one or more embodiments, the first vector forms an angle with a transverse plane of the patient’s head and is directed towards a coronal plane of the patient’s head, wherein the angle is between 0° and 90°.

[0098] In one or more embodiments, the second vector is directed substantially perpendicular towards the corresponding position of the nose bridge of the patient.

[0099] In one or more embodiments, the nasal strap portion of the headgear is resilient and is capable of returning to a contracted state for conforming the nasal strap portion of the headgear to the nose bridge of the patient after being widened to an expanded state.

[0100] In one or more embodiments, the nasal strap portion of the headgear includes elastic material stretchable to conform the nasal strap portion of the headgear to the nose bridge of the patient.

[0101] In one or more embodiments, the nasal strap portion of the headgear includes an adjustable arrangement to tighten the nasal strap portion of the headgear for conforming to the nose bridge of the patient.

[0102] In one or more embodiments, the adjustable arrangement includes one or more or a combination of a ring, a slide, a hook, a buckle, or a strap adjuster for adjusting the nasal strap portion of the headgear.

[0103] In one or more embodiments, at least one of the two or more electrical sensing elements is fixedly attached to one or both of the nasal strap portion of the headgear and the nasal interface.

[0104] In one or more embodiments, the at least one of the two or more electrical sensing elements is embedded in one or both of the nasal strap portion of the headgear and the nasal interface.

[0105] In one or more embodiments, at least one of the two or more electrical sensing elements is movably attached to one or both of the nasal strap portion of the headgear and the nasal interface in a manner so as to be translatable between different positions thereof.

[0106] In one or more embodiments, when the at least one of the two or more electrical sensing elements is movably attached to the nasal strap portion of the headgear, theat least one of the two or more electrical sensing elements is attached to a slide attachment, the slide attachment including a slide channel through which the nasal strap portion of the headgear is fitted such that the slide attachment is slidable relative to the nasal strap portion of the headgear for moving said electrical sensing element along the nasal strap portion of the headgear.

[0107] In one or more embodiments, the at least one of the two or more electrical sensing elements is removably attached thereto.

[0108] In one or more embodiments, at least one of the two or more electrical sensing elements is removably attached to one or both of the nasal strap portion of the headgear and the nasal interface.

[0109] According to an aspect, there is provided a patient interface assembly including: a nasal interface including a main portion between a first lateral portion and a second lateral portion, and at least one nasal delivery element extending from the main portion; and an electrical sensing arrangement for detecting electrical activity of a patient to monitor a depth of anaesthesia of the patient, the electrical sensing arrangement including two or more electrical sensing elements being disposed at the first lateral portion and / or the second lateral portion of the nasal interface.

[0110] In one or more embodiments, the patient interface assembly includes at least one electrical sensing element disposed at the first lateral portion of the nasal interface and at least one further electrical sensing element disposed at the second lateral portion of the nasal interface.

[0111] In one or more embodiments, the patient interface assembly includes two electrical sensing elements disposed side-by-side lengthwise at the first lateral portion of the nasal interface and / or two electrical sensing elements disposed side-by-side lengthwise at the second lateral portion of the nasal interface.

[0112] In one or more embodiments, the patient interface assembly includes two electrical sensing elements disposed at the first lateral portion of the nasal interface and side-by-side along a direction transverse to a length of the first lateral portion, and / or two electrical sensing elements disposed at the second lateral portion of the nasal interface and side-by-side along a direction transverse to a length of the second lateral portion.

[0113] In one or more embodiments, each of the two or more electrical sensing elements is an electrode.

[0114] In one or more embodiments, the electrode is an electroencephalography electrode.

[0115] In one or more embodiments, each of the two or more electrical sensing elements is in the form of a cup, a disc, a patch, a pad or at least one needle.

[0116] In one or more embodiments, at least one of the two or more electrical sensing elements includes an adhesive surface or a frictional surface.

[0117] In one or more embodiments, at least one of the two or more electrical sensing elements is fixedly attached to the nasal interface.

[0118] In one or more embodiments, the at least one of the two or more electrical sensing elements is embedded in the nasal interface.

[0119] In one or more embodiments, at least one of the two or more electrical sensing elements is movably attached to the nasal interface in a manner so as to be translatable between different positions thereof.

[0120] In one or more embodiments, the at least one of the two or more electrical sensing elements is removably attached thereto.

[0121] In one or more embodiments, at least one of the two or more electrical sensing elements is removably attached to the nasal interface.

[0122] In one or more embodiments, the patient interface assembly further includes at least one non-electrical sensing element attached to the nasal interface, wherein the at least one non-electrical sensing element includes one of a photosensing element, an optical sensing element, or a thermosensing element.

[0123] In one or more embodiments, the at least one nasal delivery element is a nasal prong.

[0124] In one or more embodiments, the nasal interface includes two nasal prongs.

[0125]

[0126] In one or more embodiments, the two nasal prongs are of different dimensions.

[0127] In one or more embodiments, the two nasal prongs are of a same dimension.

[0128] In one or more embodiments, the nasal interface includes at least one gases flow port disposed at one of (i) the main portion or (ii) the first lateral portion and / or the second lateral portion of the nasal interface, the at least one gases flow port being for receiving a gases flow, wherein the at least one gases flow port is in fluid communication with the at least one nasal delivery element.

[0129] In one or more embodiments, when the at least one gases flow port is disposed at the first lateral portion, the main portion includes a manifold, the first lateral portion includes a gases delivery side member extending from a corresponding side of the manifold, and the second lateral portion includes a non-delivery side member extending from a corresponding opposite side of the manifold, wherein an end of the gases delivery side member distal from the manifold includes a delivery inlet serving as the at least one gases flow port, wherein the at least one nasal delivery element extends from the manifold.

[0130] In one or more embodiments, when the at least one gases flow port is disposed at the second lateral portion, the main portion includes a manifold, the second lateral portion includes a gases delivery side member extending from a corresponding side of the manifold, and the first lateral portion includes a non-delivery side member extending from a corresponding opposite side of the manifold, wherein an end of the gases delivery side member distal from the manifold includes a delivery inlet serving as the at least one gases flow port, wherein the at least one nasal delivery element extends from the manifold.

[0131] In one or more embodiments, the gases delivery side member includes a collapsible portion operable to change between a normally open configuration and a collapsed configuration.

[0132] In one or more embodiments, the collapsible portion changes from the normally open configuration to the collapsed configuration upon application of a collapsing force to the collapsible portion.

[0133] In one or more embodiments, the patient interface assembly further includes a gas path connector connected to the delivery inlet.

[0134] In one or more embodiments, when the at least one gases flow port is disposed at the main portion, the at least one gases flow port is an opening in the main portion providing direct fluid access into a flow passage of the at least one nasal delivery element.

[0135] In one or more embodiments, the nasal interface includes a face mount part with an upper portion serving as the main portion from which the at least one nasal delivery element extends, and the at least one gases flow port is an aperture in the upper portion opening into the flow passage of the at least one nasal delivery element extending from the upper portion of the face mount part.

[0136] In one or more embodiments, the face mount part includes a face contacting portion, wherein the upper portion and the face contacting portion are at an angle to one another.

[0137] In one or more embodiments, the face mount part includes an auxiliary portion extending from the upper portion to the face contacting portion to form a recess capable of receiving a gases flow manifold part.

[0138] In one or more embodiments, the aperture in the upper portion is located along a segment of the upper portion forming the recess with the face contacting portion and the auxiliary portion.

[0139] In one or more embodiments, the recess includes two lateral openings for lateral insertion of the gases flow manifold part into the face mount part.

[0140] In one or more embodiments, the gases flow manifold part is at an end of a gas conduit, wherein an end of the gases flow manifold part distal from the gas conduit is closed and the gases flow manifold part has an opening along a side of the gases flow manifold part, whereby the opening of the gases flow manifold part is capable of being aligned to the aperture of the upper portion of the face mount part when inserted into the face mount part via any one of the two lateral openings of the recess.

[0141] In one or more embodiments, wherein the nasal interface includes electrical connection points for the electrical wirings of the two or more electrical sensing elements.Brief Description of Drawings

[0142] Various embodiments will now be described in greater detail with reference to the accompanying drawings in which like features are represented by like numerals. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles. It is to be understood that the embodiments shown are examples only and are not to be taken as limiting the scope as defined in the claims appended hereto. Various embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein by reference to the figures. In the following description, various embodiments are described with reference to the following drawings, in which:

[0143] FIG. 1 shows a respiratory support system according to various embodiments;

[0144] FIG. 2 shows a back view, a side view and a top view of a patient interface of the respiratory support system of FIG. 1 according to various embodiments;

[0145] FIG. 3 shows a patient facing side of an example of a nasal interface of the patient interface according to various embodiments;

[0146] FIG. 4 shows an example of how electrical sensing elements may be disposed to the patient interface according to various embodiments;

[0147] FIG. 5 to FIG. 8 show more examples of how the electrical sensing elements may be disposed to the patient interface according to various embodiments;

[0148] FIG. 9 to FIG. 1 1 show another example of how the electrical sensing elements may be disposed to the patient interface according to various embodiments;

[0149] FIG. 12 FIG. 20 show various other examples of patient interfaces according to various embodiments;

[0150] FIG. 21 shows an interface vector (or a first vector) with respect to the nose of the patient for keeping the nasal interface in place according to various embodiments;

[0151] FIG. 22 shows an electrode vector of at least one electrical sensing element (or a second vector) according to various embodiments;

[0152] FIG. 23 shows an example of a patient interface having an adjustable arrangement according to various embodiments;

[0153] FIG. 24 shows an enlarged view of the adjustable arrangement of the patient interface of FIG. 23 according to various embodiments;

[0154] FIG. 25 shows another example of a patient interface having another example of an adjustable arrangement according to various embodiments;

[0155] FIG. 26 shows an enlarged view of the adjustable arrangement of the patient interface of FIG. 25 according to various embodiments;

[0156] FIG. 27 shows a further example of an adjustable arrangement according to various embodiments;

[0157] FIG. 28 to FIG. 30 shows various other examples of patient interfaces according to various embodiments;

[0158] FIG. 31 and FIG. 32 shows patient interfaces with a headgear including a nasal strap portion according to various embodiments;

[0159] FIG. 33 shows a sequence for wearing the patient interface of FIG. 32 according to various embodiments;

[0160] FIG. 34 shows a load acting on one side of the patient interface of FIG. 32 according to various embodiments;

[0161] FIG. 35 to FIG. 37 show patient interfaces with the headgear including an ear strap portion according to various embodiments;

[0162] FIG. 38 shows a patient interface having nasal interface 232 with electrical sensing elements 252 according to various embodiments;

[0163] FIG. 39 shows an example of the nasal interface with the electrical sensing elements incorporated therein according to various embodiments;

[0164] FIG. 40A shows an example of an attachment arrangement of the nasal interface of FIG. 39 according to various embodiments;

[0165] FIG. 40B shows another example of the attachment arrangement of the nasal interface of FIG. 39 according to various embodiments;

[0166] FIG. 41 shows the electrical sensing elements 252 for the nasal interface of FIG. 39 according to various embodiments;

[0167] FIG. 42 shows a mesh separated from the electrical sensing element of FIG. 41 according to various embodiments;

[0168] FIG. 43 shows the mesh and an insulating backing separated from the electrical sensing element according to various embodiments;

[0169] FIG. 44 to FIG. 47 show an example of the nasal interface for the patient interfaces according to various embodiments;

[0170] FIG. 48 to FIG. 50 show another example of the nasal interface for the patient interfaces according to various embodiments; and

[0171] FIG. 51 shows an end of the conduit with an integrated connector according to various embodiments;

[0172] FIG. 52 is an example of a patient interface having a headgear including an overhead strap portion and / or a chin strap portion;

[0173] FIG. 53 is an example of a patient interface having a headgear including an overhead strap portion with one or more adhesive patches;

[0174] FIG. 54 is an example of a patient interface having a headgear one or more hook portions configured to secure behind the patient’s ears;

[0175] FIG. 55 and FIG. 56 are examples of a patient interface having a headgear including a strap portion extending around the back of the patient’s head, and one or more substantially rigid arms providing the two or more electrical sensing elements;

[0176] FIG 57 is an example of a patient interface including in-ear speakers for providing audible stimulus to which the patient’s response may be monitored by the one or more sensing elements.Detailed Description

[0177] Embodiments are discussed herein by reference to the drawings which are not to scale and are intended merely to assist with explanation of the invention. Embodiments described below in the context of the apparatus, components, devices, and systems are analogously valid for the respective methods, and vice versa. Furthermore, it will be understood that the embodiments described below may be combined, for example, a part of one embodiment may be combined with a part of another embodiment as would be understood by one of skill in the art. Throughout the figures and specification, the same reference numerals may be used to designate the same or similar components, and redundant descriptions thereof may be omitted.

[0178] It should be understood that the terms “on”, “over”, “top”, “bottom”, “down”, “side”, “back”, “left”, “right”, “front”, “lateral”, “side”, “up”, “down” etc., when used in the following description are used for convenience and to aid understanding of relative positions or directions, and not intended to limit the orientation of any device, or structure or any part of any device or structure. In addition, the singular terms “a”, “an”, and “the” include plural references unless context clearly indicates otherwise. Similarly, the word “or” is intended to include “and” unless the context clearly indicates otherwise.

[0179] In this specification, unless the context requires otherwise, references to “comprise”, “comprising” and other variations of this term are to be interpreted inclusively rather than exclusively / exhaustively. Thus, “comprise” is to be understood as meaning “includes”, rather than “consists [solely] of”.

[0180] In this specification, unless the context requires otherwise, references to “distributed to” are to be interpreted to include distributed on, distributed along and distributed with respect to e.g. a headgear and / or nasal interface or and may include distributed in a manner that is moveable e.g. by sliding along a headgear or nasal interface.

[0181] In this specification, “high flow”, “high flows”, “high-flow” or other equivalent terminology means, without limitation, any gas flow with a flow rate that is higher than usual / normal, such as higher than the normal inspiration flow rate of a healthy patient. Alternatively, or additionally, it can be higher than some other threshold flow rate that is relevant to the context - for example, where providing a gas flow to a patient (or a subject) at a flow rate to meet or exceed inspiratory demand, that flow rate might be deemed “high flow” as it is higher than a nominal flow rate that might have otherwise been provided. “High flow” is therefore context dependent, and what constitutes “highflow” depends on many factors such as the health state of the patient, type of procedure / therapy / support being provided, the nature of the patient (big, small, adult, child) and the like. Those skilled in the art know from context what constitutes “high flow”. It is a magnitude of flow rate that is over and above a flow rate that might otherwise be provided.

[0182] But, without limitation, some indicative values of high flow can be as follows.

[0183] In some configurations, delivery of gases to a patient at a flow rate of greater than or equal to about 5 or 10 litres per minute (5 or 5 10 LPM or L / min).

[0184] In some configurations, delivery of gases to a patient at a flow rate of about 5 or 10 LPM to about 150 LPM, or about 15 LPM to about 95 LPM, or about 20 LPM to about 90 LPM, or about 25 LPM to about 85 LPM, or about 30 LPM to about 80 LPM, or about 35 LPM to about 75 LPM, or about 40 LPM to about 70 LPM, or about 45 LPM to about 65 LPM, or about 50 LPM to about 60 LPM. For example, according to those various embodiments and configurations described herein, a flow rate of gases supplied or provided to an interface via a system or from a flow source or flow modulator, may comprise, but is not limited to, flows of at least about 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 1 10, 120, 130, 140, 150 LPM, or more, and useful ranges may be selected to be any of these values (for example, about 20 LPM to about 90 LPM, about 40 LPM to about 70 LPM, about 40 LPM to about 80 LPM, about 50 LPM to about 80 LPM, about 60 LPM to about 80 LPM, about 70 LPM to about 100 LPM, about 70 LPM to about 80 LPM).

[0185] In “high flow” the gas delivered will be chosen depending on for example the intended use of a therapy and / or respiratory support. Gases delivered may comprise a percentage of oxygen. In some configurations, the percentage of oxygen in the gases delivered may be about 15% to about 100%, about 20% to about 100%, or about 30% to about 100%, or about 40% to about 100%, or about 50% to about 100%, or about 60% to about 100%, or about 70% to about 100%, or about 80% to about 100%, or about 90% to about 100%, or about 100%, or 100%.

[0186] In some embodiments, gases delivered may comprise a percentage of carbon dioxide. In some configurations, the percentage of carbon dioxide in the gases delivered may be more than 0%, about 0.3% to about 100%, about 1% to about 100%, about 5% to about 100%, about 10% to about 100%, about 20% to about 100%, or about 30% to about 100%, or about 40% to about 100%, or about 50% to about 100%,or about 60% to about 100%, or about 70% to about 100%, or about 80% to about 100%, or about 90% to about 100%, or about 100%, or 100%.

[0187] Flow rates for “high flow” for premature / infants / paediatrics (with body mass in the range of about 1 kg to about 30 kg, or less than 1 kg) can be different. The flow rate can be set to 0.4-8 L / min / kg with a minimum of about 0.5 L / min and a maximum of about 70 L / min. For patients under 2 kg maximum flow may be set to up to about 8 L / min. Also, for example, for a 2kg patient the flow rates would be about 0.8LPM to 16LPM.

[0188] High flow has been found effective in meeting or exceeding the patient's normal real inspiratory flow, to increase oxygenation of the patient and / or reduce the work of breathing. Additionally, high flow therapy and / or respiratory support may generate a flushing effect in the nasopharynx such that the anatomical dead space of the upper airways is flushed by the high incoming gas flows. This creates a reservoir of fresh gas available for each and every breath, while minimising re-breathing of carbon dioxide, nitrogen, etc.

[0189] By example, a respiratory support system 100 for high flow is described below with reference to FIG. 1 . High flow may be used as a means to promote gas exchange and / or respiratory support through the delivery of oxygen and / or other gases, and through the removal of CO2 from the patient’s airways. Thus, patient oxygenation is improved by increasing the flow rate of gases. High flow may be particularly useful prior to, during or after a medical and / or anaesthetic procedure.

[0190] When used prior to a medical procedure, high gas flow can pre-load the patient with oxygen (i.e., increase the reservoir of oxygen in the blood and / or lungs) so that their blood oxygen saturation level and volume of oxygen in the lungs is higher than normal in order to provide an oxygen buffer. This may be useful in reducing the risk or preventing desaturation for example when the patient is sedated and whose respiratory function has been compromised or been purposely diminished and / or when the patient is in an apnoeic phase during the medical procedure e.g. intubation.

[0191] A continuous supply of oxygen is important to sustain healthy respiratory function during medical procedures (such as during anaesthesia) where respiratory function might be compromised (e.g., diminishes or stops). When this supply is compromised, conditions such as hypoxia and / or hypercapnia can occur. During medical procedures such as anaesthesia and / or sedation, patient breathing is monitored to detect if spontaneous breathing is diminished or ceases. If oxygen supplyand / or CO2 removal is compromised, the clinician stops the medical procedure and facilitates oxygen supply and / or CO2 removal. This can be achieved for example by manually ventilating the patient for example through bag mask ventilation.

[0192] High flow respiratory support may be provided as a continuous form of respiratory support for a patient. An example of continuous respiratory support is where the patient receives high flow respiratory support from pre-operative stage, for example preoxygenation, to a post operative stage continuously. Providing high flow respiratory support prior to and / or during and / or after a medical procedure can reduce the risk of patient desaturation which can in turn reduce the likelihood of clinician intervention. For example, reduce the likelihood of needing to stop the medical procedure to manually ventilate the patient using bag mask ventilation.

[0193] In some circumstances it is possible to apply a mask over a nasal interface. Such a nasal interface may have a portion designed to collapse under the mask (see for example FIG. 44 to FIG. 47) so that an adequate seal can be achieved between the mask and the patient’s face, eliminating the need to remove the nasal cannula before applying the mask.

[0194] It will be appreciated that a mask that is used for sedation / ventilation (not necessarily limited to a bag mask) may also be used for preoxygenation and also for monitoring patient parameters such as end tidal CO2, etc. Such a mask may also be applied over a nasal interface with a collapsible portion.

[0195] In addition to improving patient oxygenation by increasing the flow rate of gases, advantages of high gas flow can include that the high gas flow increases pressure in the airways of the patient, thereby providing pressure support that opens airways, the trachea, lungs / alveolar and bronchioles. The opening of these structures enhances oxygenation, and to some extent assists in removal of CO2 and / or can help support patients with collapsed areas of the lung.

[0196] When humidified, the high gas flow can also prevent airways from drying out, mitigating mucociliary damage, reducing risk of infection and reducing risk of laryngospasms and risks associated with airway drying such as nose bleeding, pulmonary aspiration (as a result of nose bleeding), and airway obstruction, swelling and bleeding. Another advantage of high gas flow is that the flow can clear smoke created during surgery in the air passages. For example, smoke can be created by lasers and / or cauterizing devices.

[0197] FIG. 1 shows the respiratory support system 100 according to various embodiments. The system 100 may be configured to provide high flow respiratory support and / or high flow therapy. The respiratory support system 100 may include a flow generator 102. The flow generator 102 may be configured to generate gas flows that are passed through the respiratory support system 100. The flow generator 102 may be configured to generate gas flows that are provided to a patient (or a subject) at flow rates described elsewhere in the present specification. The flow generator 102 may pass the air and / or other gases to a humidifier 104. The humidifier 104 may be configured to heat and humidify gas flows generated by the flow generator 102. Thus, the flow of gases provided to the patient may have an absolute humidity of about 10mg / L to 45 mg / L. The flow of gases may have a relative humidity of about 10% to 100%, or about 80% to 100%, or about 100%. The flow of gases may have a flow rate of about 5L / min to 90L / min, or 10L / min to 70L / min. The flow of gases may have a humidity of about 20mg / L to 35 mg / L. The flow of gases may have a flow rate of about 70L / min. The flow of gases may have a humidity of about 30mg / L. The flow of gases may be heated to 21cC to 42OC, or 25°C to 40°C, or 31 °C to 37°C, or about 31 °C, or about 37°C.

[0198] In some configurations, the flow generator 102 may include a blower adapted to receive gases from the environment outside of the respiratory support system 100 and propel them through the respiratory therapy system 100. In some configurations, the flow generator 102 may include some other gas generation means. For example, in some configurations, the flow generator 102 may include or receive a gas source available from a hospital gas outlet (e.g., oxygen or air), or one or more containers of compressed air and / or another gas and one or more valve arrangements adapted to control the rate at which gases leave the one or more containers. In some configurations, the flow generator may include a proportional value which is operable to supply a desired flow rate of gases to the patient. As another example, in some configurations, the flow generator 102 may include an oxygen concentrator. In some configurations, the flow generator 102 may be adapted to deliver a high flow respiratory support and / or high flow therapy. In some embodiments, the flow source may include a compressed gas source, a device (such as e.g. a proportional value) that modifies the flow from a compressed gas source and / or a flow generator which generates a gas flow.

[0199] The respiratory support system 100 may include a housing 106 that at least partially houses both the flow generator 102 and the humidifier 104 e.g., the respiratory support system 100 may include an integrated flow generator / humidifier apparatus. In other configurations the flow generator 102 and humidifier 104 may have separate housings, and / or be separate components. A hardware controller 108 is shown to be in electronic communication with the flow generator 102 and the humidifier 104, although in some configurations the hardware controller 108 might only communicate with the flow generator 102 or the humidifier 104. In some configurations, the flow generator 102 and the humidifier 104 may each have their own controller, which may or may not be in communication with one another. The hardware controller 108 may include a microcontroller or some other architecture configured to direct the operation of controllable components of the respiratory support system 100, including but not limited to the flow generator 102 and / or the humidifier 104.

[0200] An input / output module 1 10 is shown to be in electronic communication with the controller 108. The input / output module 1 10 may be configured to allow a user (e.g., a person attending to the patient) to interface with the controller 108 to facilitate the control of controllable components of the respiratory support system 100, including but not limited to the flow generator 102 and / or the humidifier 104, and / or view data regarding the operation of the respiratory support system 100 and / or its components. The input / output module 1 10 might include, for example, one or more buttons, knobs, dials, switches, levers, touch screens, speakers, displays and / or other input or output peripherals that the user might use to view data and / or input commands to control components of the respiratory support system 100.

[0201] As further shown in FIG. 1 , a supplementary gas source 1 16 may be used to add one or more supplementary gases to the gases flowing through the respiratory support system 100. The one or more supplementary gases may join the gas flow generated by the flow generator 102. The supplementary gas source 1 16 may be configured to deliver one or more supplementary gases including but not limited to air, oxygen (02), carbon dioxide (CO2), nitrogen (N2), nitrous oxide (NO), anaesthetic agents and / or heliox (a mixture of helium and oxygen). The supplementary gas source 1 16 may deliver the one or more supplementary gases via a first supplementary gas conduit 120 to or towards the flow generator 102, and / or may deliver the one or more supplementary gases via a second supplementary gas conduit 124 to a location in the flow passage between the flow generator 102 and the humidifier 104. One or moresupplementary flow valves 1 18, 122 may be used to control the rates at which the one or more supplementary gases can flow from the supplementary gas source 1 16 and through the first and / or second supplementary gas conduits 120, 124. One or more of the supplementary flow valves 1 18, 122 may be in electronic communication with the controller 108 or a separate controller, which may in turn control the operation and / or state of the one or more supplementary flow valves 1 18, 122. In some configurations, one or more of the supplementary flow valves 1 18, 122 may be manually adjusted by a user. In some examples a manually adjustable supplementary flow value may include e.g. a flow meter such as a wall-mounted flow meter. In other configurations, the supplementary gas source 1 16 may be configured to add one or more supplementary gases downstream of the humidifier 104. In other configurations, supplementary gas source 1 16 may be configured to add one or more supplementary gases into the humidifier 104, e.g., into a humidification chamber containing a body of water and engageable with a heater base, the water to be heated by a heating element to humidify a flow of gases to the patient.

[0202] As shown in FIG. 1 , a conduit 1 12 extending from the humidifier 104 may link the humidifier 104 to a patient interface 230 (or a patient interface assembly). The patient interface 230 may be for wearing on a patient’s head. The conduit 112 may include a conduit heater 1 14 adapted to heat gases passing through the conduit 1 12. In other configurations the conduit heater 1 14 may not be present. In some embodiments, an optional filter (not shown) may be arranged between the conduit 112 and the patient interface 230. The patient interface 230 is shown to include a nasal interface 232, although it should be understood that in some configurations, other patient interfaces may be suitable. For example, in some configurations, the patient interface 230 may include a sealing or non-sealing nasal interface 232, and may include a nasal mask, an oral mask, an oro-nasal mask, a full-face mask, a nasal pillows mask, a nasal cannula, an endotracheal tube, tracheostomy tube, a combination of the above or some other gas conveying system. In an embodiment, the patient interface 230 may include a non-sealing nasal interface 232, such as a nasal cannula, which allows gases to be exchanged with the environment. For example, the non-sealing nasal interface may allow carbon dioxide to be removed and / or cleared from the patient’s airways while the patient (or the subject) receives a gas flow from the system 100. Further, in some embodiments, the patient interface 230 may be in the form of a nasal interface, such that the system does not interferewith other oral airway equipment and / or devices, for example, a tracheal tube in an intubation procedure. In another embodiment, the patient interface 230 may include a sealing nasal interface 232, such as a nasal mask, which seals around the nose of the patient, or under the nose of the patient or both the nose and the mouth of the patient.

[0203] According to various embodiments, the patient interface 230 may include an electrical sensing arrangement 250 (for example, see FIG. 2). The electrical sensing arrangement 250 may communicate with the controller 108 to process signals from the electrical sensing arrangement 250 in various ways. For example, the controller 108 may filter or process raw signals, and / or display parameters associated with the filtered / processed signals on the input / output module 1 10. The signals from the electrical sensing arrangement 250 may be sent to the controller 108 wirelessly or via wires. As an example, the wires may be extending along lumen 112c of the conduit 1 12 (for example, see FIG. 51 ). The signals from the electrical sensing arrangement 250 may be communicated or exchanged with a device external to system 100.

[0204] FIG. 2 shows a back view, a side view and a top view of the patient interface 230 of the respiratory support system 100 of FIG. 1 according to various embodiments. As shown, according to various embodiments, the patient interface may include the nasal interface 232. In some embodiments, the nasal interface 232 may be nonsealing (i.e., may not form an airtight seal with the nose of the patient or around the nose and the mouth of the patient), which allows exchanges of gases with the environment. Accordingly, when worn, the patient (or the subject) may receive gases flow via the nasal interface 232 and may continue to directly exchange gases with the environment. An example of the nasal interface 232 that is non-sealing may include a nasal cannula. In other embodiments, the nasal interface 232 may form a seal with the nose of the patient or both the nose and the mouth of the patient when worn. Accordingly, when worn, the patient (or the subject) may receive gases flow via the nasal interface 232 and may not exchange gases directly with the environment. Examples of the nasal interface 232 capable of forming a seal may include, but not limited to, a nasal mask, an oral mask, an oro-nasal mask, a full-face mask, or a nasal pillows mask,

[0205] FIG. 3 shows an example of the nasal interface 232 according to various embodiments. According to various embodiments, the nasal interface 232 may include a main portion 242, a first lateral portion 244 and a second lateral portion 246. The main portion 242 may be between the first lateral portion 244 and the second lateralportion 246. The main portion 242 may be a portion of the nasal interface 232 for placing or interacting with a nasal region of the patient. For example, the main portion 242 may be configured for abutting or resting against or placed adjacent to the nose of the patient. Further, the first lateral portion 244 and the second lateral portion 246 may be extending from two opposite lateral sides of the main portion 242 of the nasal interface 232. In other words, the first lateral portion 244 and the second lateral portion 246 of the nasal interface 232 may be opposite each other across the main portion 242 of the nasal interface 232. According to various embodiments, when worn, the main portion may be positioned at the nose of the patient, and the first lateral portion 244 and the second lateral portion 246 may extend away from opposite lateral sides of the nose of the patient. For example, in an embodiment, when worn, the main portion 242 of the nasal interface 232 may lie across the two nostrils of the nose of the patient, the first lateral portion 244 may extend from a left side of the main portion 242 and away from a left side of the nose towards a left cheek of the patient, and the second lateral portion 246 may extend from a right side of the main portion 242 and away from a right side of the nose towards a right cheek of the patient.

[0206] As shown in FIG. 3, according to various embodiments, the nasal interface 232 may include at least one nasal delivery element 348 disposed at the main portion 242 of the nasal interface 232. The at least one nasal delivery element 348 may be configured to deliver or supply or discharge gases from the nasal interface 232 to the nose of the patient. Accordingly, the at least one nasal delivery element 348 may serve as an outlet for gases flow from the nasal interface 232. In various example, gases flow entry may be from one or both sides of the nasal interface 232 (e.g. along one or both of the first lateral portion 244 and the second lateral portion 246) and gases flow exit may be via the at least one nasal delivery element 348. Accordingly, the gases may flow into the nasal interface 232 from a single side of the nasal interface 232 or from both sides of the nasal interface 232. Further, the gases may exit the nasal interface 232 via the at least one nasal delivery element 348.

[0207] According to various embodiments, the at least one nasal delivery element 348 may protrude or extend from the main portion 242 of the nasal interface 232. Accordingly, the at least one nasal delivery element 348 may be in the form of a protrusion or an appendage extending outwardly from the main portion 242 of the nasal interface 232. Further, the at least one nasal delivery element 348 may be configured to be inserted or fitted or positioned in a nare of the nose of the patient.Hence, the at least one nasal delivery element 348 may be shaped or angled or dimensioned for extending from the main portion 242 of the nasal interface 232 into the nasal cavity of the nose of the patient. As an example, the at least one nasal delivery element 348 may be in the form of a nasal prong.

[0208] According to various embodiments, the nasal interface 232 may include two nasal delivery elements 348. The two nasal delivery elements 348 may be configured to be inserted or fitted or positioned one in each of the nares of the nose of the patient. For example, the two nasal delivery elements 348 may be two nasal prongs.

[0209] According to various embodiments, the nasal delivery element 348 (e.g., nasal prong) may be shaped to fit the contours of the nares of the nose of the patient. For example, the nasal delivery element 348 may be tubular in shape and may be curved to point an outlet (or free outlet end) of the nasal delivery element 348 towards the back of the patient’s head when in use. Further, the nasal delivery element 348 may include an internal and / or external cross-sectional shape that is elliptical, for example a circle, or substantially elliptical, for example an oval. The cross-section of the nasal delivery element 348 may be transverse to a direction of flow through the nasal delivery element 348. According to various embodiments, the shape and / or dimensions of the nasal delivery element 348 may be consistent or may change along its length. According to various embodiments, when there are two nasal delivery elements 348, the two nasal delivery elements 348 may be angled towards a central plane bisecting the main portion 242 between the two nasal delivery elements 348.

[0210] According to various embodiments, the at least one nasal delivery element 348 may be configured to be non-sealing when inserted or fitted or positioned in the corresponding nare of the nose of the patient. For example, the at least one nasal delivery element 348 may be a non-sealing nasal prong. In other words, a gap may exist between the at least one nasal delivery element 348 and the corresponding nare of the nose of the patient. This may allow continuous flow of gases between the at least one nasal delivery element 348 and the corresponding nare of the nose of the patient. According to various embodiments, when there are two nasal delivery elements 348, both nasal delivery elements 348 may be non-sealing, or one of the two nasal delivery elements 348 may be non-sealing, or both the nasal delivery elements 348 may be sealing. According to various embodiments, when there is only one nasal delivery elements 348, the one nasal delivery element 348 may be non-sealing orsealing with the corresponding nare while leaving the other nare unoccluded such that the nasal interface 232 as a whole may be non-sealing.

[0211] According to various embodiments, when there are two nasal delivery elements 348 (e.g., two nasal prongs), both nasal delivery elements 348 may have the same dimensions. Accordingly, the two nasal delivery elements 348 may be a mirror image of each other. For example, the two nasal delivery elements may have a same length, same internal diameters, same external diameters, same curvature, etc. Hence, both the nasal delivery elements 348 may be sealing or non-sealing with the nares of the nose (e.g. both are sealing nasal prongs, or both are non-sealing nasal prongs). According to various embodiments, when there are two nasal delivery elements 348 (e.g., two nasal prongs), both nasal delivery elements 348 may have different dimensions. For example, the two nasal delivery elements 348 may have different internal diameters. Accordingly, a flow passage of the nasal delivery elements 348 with a smaller internal diameter may provide a more restricted flow. As another example, the two nasal delivery elements 348 may have different external diameters. Accordingly, one of the two nasal delivery elements 348 may form a seal with the corresponding nare of the nose (e.g., a sealing nasal prong), while the other nasal delivery element 348 may be non-sealing with the corresponding nare of the nose (e.g., non-sealing nasal prong).

[0212] Referring back to FIG. 1 and FIG. 2, according to various embodiments, the patient interface 230 may include a headgear 234. The headgear 234 may be any suitable item for wearing on the patient’s head. For example, including but not limited to, a harness, a brace, a helmet, a cap, a hat, a hood, a bonnet, a wrap, a net, a loop, or a strap. The patient interface 230 and the headgear 234 may be permanently coupled or integrated together in a permanent arrangement. Alternatively, the patient interface 230 and the headgear 234 may be removable couplable via a fastener, which may include but is not limited to a quick release clip, quick release buckle, quick release latch, complimentary hook and loop attachment structures, magnets etc. According to various embodiments, the headgear 234 may be configured to retain the nasal interface 232 in place. Further, the headgear 234 may hold the nasal interface 232 by the first lateral portion 244 and the second lateral portion 246 of the nasal interface 232. Accordingly, the nasal interface 232 may be retained in place by the headgear 234 with the first lateral portion 244 and the second lateral portion 246 of the nasal interface 232 held by the headgear 234. Thus, portions of the headgear 234may extend respectively from the first lateral portion 244 and the second lateral portion 246 of the nasal interface 232 for holding the nasal interface 232. In an example, the headgear 234 may be attached or connected or coupled or joined or fixed to the nasal interface 232 so as to hold the nasal interface 232. In another example, the headgear 234 may support or bear or carry the nasal interface 232 so as to hold the nasal interface 232.

[0213] According to various embodiments, the headgear 234 and the nasal interface 232 may together form an article to be worn on the patient’s head. Accordingly, when worn, the headgear 234 may serve to keep the nasal interface 232 in place on the patient’s head. Hence, the headgear 234 may retain the nasal interface 232 to position and maintain the nasal interface 232 with respect to the patient’s head such that the main portion 242 of the nasal interface 232 may be at the nasal region of the patient. For example, the main portion 242 of the nasal interface 232 may be positioned and maintained to abut or rest against or placed adjacent to the nose of the patient, such as to lie across the two nostrils of the nose of the patient.

[0214] According to various embodiments, the patient interface 230 may include an electrical sensing arrangement 250. The electrical sensing arrangement 250 may be configured to detect electromagnetic activity such as electrical activity or electrical biosignals from the patient (or the subject). For example, the electrical sensing arrangement 250 may detect electrical activity or electrical signals of the brain of the patient (e.g., brain waves), and / or electrical activity of bodily parts such as muscles and / or nerves. Accordingly, the electrical sensing arrangement 250 may be configured as an electrical activity detector including but not limited to an electroencephalogram (EEG) monitor, an auditory evoked potentials (AEP) monitor, or an electromyogram (EMG) monitor.

[0215] Further, the electrical sensing arrangement 250 may be configured to monitor a depth of anaesthesia (DoA) (or depth of sedation or level of consciousness) of the patient based on the detected electrical activity of the patient. When the anaesthetic drug is administered to the patient (or the subject), the electrical activity of the patient (e.g., of the patient’s brain) may be altered by the anaesthetic drug. Accordingly, the electrical sensing arrangement 250 may detect a change in the electrical activity of the patient (e.g., of the patient’s brain). Thus, the electrical sensing arrangement 250 may determine the DoA based on the detected electrical activity. For instance, the electrical sensing arrangement 250 may determine whether the patient (or the subject) is awakeand aware, or whether the patient (or the subject) is sedated, or whether the patient (or the subject) is becoming apnoeic based on the detected electrical activity.

[0216] According to various embodiments, the electrical sensing arrangement 250 may be configured as part of an EEG monitor to detect a change in brain activity, for example changes in brain waves due to the introduction of anaesthetic drugs. A patient that is awake and aware may show a first pattern on a monitoring device, as detected by the electrical sensing arrangement 250. The same patient under the influence of anaesthetic drugs may show a second pattern on the monitoring device, as detected by the electrical sensing arrangement 250, wherein the first pattern is different from the second pattern and the difference is indicative of the patient becoming sedated i.e. induced into a particular DoA. Conversely, as the effects of anaesthetic agents wear off, there may be a change in the amplitude and / or frequency of brain activity, which can hence be monitored to determine that the patient is waking up. Hence, the electrical sensing arrangement 250 may detect such a change to determine that the patient is waking up. According to some other embodiments, the electrical sensing arrangement 250 may be configured as an AEP monitor to measure a patient’s EEG in response to auditory stimuli. According to some other embodiments, the electrical sensing arrangement 250 may be configured as an EMG monitor to measure muscular activity or electrical activity of muscles and / or nerves in response to an applied stimulus.

[0217] According to various embodiments, the electrical sensing arrangement 250 may include two or more electrical sensing elements 252. The two or more electrical sensing elements 252 may be distributed to either one or both of the headgear 234 and the nasal interface 232. Accordingly, the two or more electrical sensing elements 252 may be at the headgear 234 only, or may be at the nasal interface 232 only, or may be at both the headgear 234 and the nasal interface 232.

[0218] According to various embodiments, each of the two or more electrical sensing elements 252 may be configured to detect electrical activity through the skin of the patient. Accordingly, each of the two or more electrical sensing elements 252 may be adapted to contact the skin of the patient and to detect electrical activity under the skin of the patient. For example, each of the two or more electrical sensing elements 252 may detect the electrical activity via conduction through the skin and subcutaneous tissue and / or bone of the patient. According to various embodiments, each of the two or more electrical sensing elements 252 may be an electrode. The electrode may bean electrical conductor for making electrical contact between biological structures and electronic components of the patient interface assembly. For example, each of the two or more electrical sensing elements 252 may be an electrode for electrophysiological recording. Hence, each of the two or more electrical sensing elements 252 may be for detecting electrical activity associated with a physiological process, such as the function of a body or bodily part of the patient. As a further example, each of the two or more electrical sensing elements 252 may be an electroencephalography (EEG) electrode. Accordingly, each of the two or more electrical sensing elements 252 may be for detecting the electrical activity of the brain associated with a neurophysiological process of the brain, such as electrical activity created by post-synaptic neuron potentials in the outer layer of the brain (the cortex).

[0219] According to various embodiments, the patient interface 230 may be configured to combine or integrate the nasal interface 232 and the electrical sensing arrangement 250 in a manner so as to provide a reliable detection and / or monitoring of the electrical activity of the patient and to provide reliable flow of gases to the patient (or the subject) at the same time. According to various embodiments, the patient interface 230 may be configured to achieve one or more of the following: minimally obstructs access to regions of the patient’s face, reliably provide nasal high flow whilst monitoring the patient’s DoA, and minimizes the number of steps a user has to take to position both the nasal interface and DoA monitor at appropriate positions on the patient’s face, for example where their positions could have synergistic effects on their respective functions.

[0220] According to various embodiments, since the electrical sensing arrangement 250 is configured to detect or monitor electrical activity of the patient, the two or more electrical sensing elements 252 may be configured for contacting, touching or adhering to a skin of the patient. In some configurations, one or more features of the electrical sensing elements 252 may pierce or penetrate the skin surface. In some configurations, one or more sensing elements may include a device capable of conducting and / or detecting electromagnetic activity. In some examples, the electromagnetic activity may include brain activity, and / or electromagnetic activity in another body part or organ. According to various embodiments, each of the two or more electrical sensing elements 252 may be in the form including, but not limited to, a cup, a disc, a patch, a pad, at least a needle, or a combination thereof for contacting, touching, or adhering to the skin of the patient. According to various embodiments, atleast one (or each) of the two or more electrical sensing elements 252 may include an adhesive surface or friction surface. The adhesion and / or friction provided by such surfaces may provide resistance against translation, i.e. movement of at least one (or each) of the two or more electrical sensing elements 252 while the patient interface 230 is worn. Accordingly, the adhesive surface or the friction surface of the at least one (or each) of the two or more electrical sensing elements 252 may attach said electrical sensing elements 252 to the skin of the patient in a non-movable manner such that said electrical sensing elements 252 may be kept in place while the patient interface 230 is being worn on the patient (or the subject). Alternatively or additionally, the headgear may include one or more adhesive features to provide resistance against movement of at least one (or each) of the two or more electrical sensing elements 252 while the patient interface 230 is worn.

[0221] According to various embodiments, while a minimum of two electrical sensing elements 252 may be sufficient to detect electrical activity, the patient interface 230 may include three or more electrical sensing elements 252 to improve a signal quality of the electrical activity detected. With a minimum of three electrical sensing elements, sensitivity of detection and signal quality of the detected electrical activity may be enhanced. For example, in some configurations, one or more of the electrodes may be used as a reference electrode to remove or reduce noise (e.g., noise caused by Frontalis muscle activity recorded by EMG), while in some configurations where there is a plurality of electrodes, signals may be referenced to each other to remove any noise or reduce noise to improve the signal to noise ratio. Removing or reducing signal noise may be particularly beneficial when detecting EMG signals using electrical sensing elements 252 situated on the front of the head such as on the face, particularly the forehead.

[0222] FIG. 4 shows an example of how the two or more electrical sensing elements 252 may be disposed to the patient interface 230 according to various embodiments. FIG. 5 to FIG. 8 show more examples of how the two or more electrical sensing elements may be disposed to the patient interface 230 according to various embodiments. FIG. 9 to FIG. 1 1 show more examples of how the two or more electrical sensing elements 252 may be disposed to the patient interface 230 according to various embodiments. It is understood that the various examples as shown in FIG. 4 to FIG. 1 1 are applicable to disposing the two or more electrical sensing elements to the headgear 234 and / or the nasal interface 232. According to various embodiments,the two or more electrical sensing elements 252 may be attached or coupled to the patient interface 230. For example, the two or more electrical sensing elements 252 may be attached or coupled to the patient interface 230 in a permanent manner (for example see FIG. 4 to FIG. 6 and FIG. 8) via attachment method including, but not limited to, overmoulding, intramoulding, welding, ultrasonic welding etc. As another example, the two or more electrical sensing elements 252 may be attached or coupled to the patient interface 230 in a removable manner (for example see FIG. 7) via removable fastener including, but not limited to, quick release clip, quick release buckle, quick release latch, etc. As yet another example, the two or more electrical sensing elements may be attached or coupled to the patient interface 230 in a manner so as to be movable relative to the patient interface 230 (for example see FIG. 9 to FIG. 1 1 ) via movable attachment such as a slidable attachment.

[0223] According to various embodiments, at least one of the two or more electrical sensing elements 252 may be fixedly attached to either one or both of the headgear 234 and the nasal interface 232. Referring to FIG. 4, the two or more electrical sensing elements 252 may be overmoulded to the headgear 234 and / or the nasal interface 232 (e.g., overmoulded to a strap thereof). For example, as shown, each electrical sensing elements 252 may be separately overmoulded to the headgear 234 or the nasal interface 232 in a spaced apart configuration. As further shown, each electrical sensing element 252 may be incorporated into an attachment member 254a with an overmould member 256 fixedly attaching the attachment member 254a to a strap 258a of the headgear 234 or the nasal interface 232. Referring to FIG. 5, the two or more electrical sensing elements 252 may be in the form of a strip of electrical sensing elements 252 overmoulded to the headgear 234 or the nasal interface 232 (e.g., overmoulded to a strap thereof). For example, as shown, the electrical sensing elements 252 may be arranged in series to form a strip of electrical sensing elements 252 and the entire strip, as a whole, may be overmoulded to the headgear 234 or the nasal interface 232. As further shown, the electrical sensing elements 252 may be lined along a single elongated attachment member 254b, and the single elongated attachment member 254b may be overmoulded to a strap 258b of the headgear 234 or the nasal interface 232. Referring to FIG. 6 and FIG. 7, the two or more electrical sensing elements 252 may be arranged in series to form a strip of electrical sensing elements 252 and the ends of the strip of electrical sensing elements 252 may be respectively coupled or attached to either one or both of the headgear 234 and thenasal interface 232 (e.g., coupled or attached to corresponding ends thereof). As shown in FIG. 6, each electrical sensing element 252 may be incorporated to an attachment member 254c. Further, the attachment members 254c may be interconnected by a link member 255 to form a strip. For example, the attachment members 254c may be formed or joined together. As a further example, the attachment members 254c may be formed or joined together via being integrally moulded together or being integrally joined together or being cut / punched out as a single piece. Respective ends of the strip may then be coupled or attached to corresponding ends of the straps 258c of the headgear 234 or the nasal interface 232, or the nasal interface tubing, or coupled or attached to nodes 261 , 263. As shown in FIG. 7, the electrical sensing elements 252 may be lined along a single elongated attachment member 254d and the ends of the single elongated attachment member 254d may be coupled or attached to corresponding ends of the straps 258d of the headgear 234 or the nasal interface 232. Referring to FIG. 8, the two or more electrical sensing elements 252 may be embedded into the headgear 234 or the nasal interface 232 (e.g., embedded in a strap thereof). For example, as shown, the electrical sensing elements 252 may be incorporated or encapsulated in a strap 258e of the headgear 234 or the nasal interface 232 in a manner so as to be lined along the strap 258e of the headgear 234 or the nasal interface 232. Therefore, according to various embodiments, the at least one of the two or more electrical sensing elements 252 may be fixedly attached via embedding in or overmoulding to either the headgear 234 or the nasal interface 232. The at least one of the two or more electrical sensing elements 252 may also be fixedly attached via connecting two ends of the strip of electrical sensing elements 252 to either one or both of the headgear 234 and the nasal interface 232.

[0224] According to various embodiments, when the electrical sensing element 252 is fixedly attached to either one or both the headgear 234 and the nasal interface 232, the electrical sensing element 252 may serve as an anchor for the patient interface 230. Further, when the patient interface 230 is being worn on the patient’s head, the electrical sensing element 252 may adhere to respective positions on the patient’s head and may be prevented from translating i.e. moving away from said positions. Accordingly, with the electrical sensing element 252 being fixedly attached to the patient interface 230, the electrical sensing element 252 may anchor the patient interface 230 to the patient’s head and prevent relative movement between the patientinterface 230 and the patient’s head. Thus, the patient interface 230 may be prevented from shifting its position or moving relative to the patient’s head, by the electrical sensing element 252 fixedly attached thereto, when the patient interface 230 is worn. In particular, if the electrical sensing element 252 has the adhesive surface or the frictional surface, the adhesive surface or the frictional surface may enhance the electrical sensing element 252 for anchoring. According to various embodiments, the attachment member 254a, 254b, 254c, 254d may include an adhesive surface or a frictional surface to facilitate anchoring. Adhesion may increase resistance to translation i.e. movement of the patient interface 230 and may increase stability of the patient interface 230 during respiratory support or therapy (important with high flows and potentially mobile patients). Further, adhesion may also improve the quality of signal by reducing errors caused by motion of the electrical sensing element 252.

[0225] Referring to FIG. 9 to FIG. 11 , according to various embodiments, at least one of the two or more electrical sensing elements 252 may be movably attached to either one or both of the headgear 234 and the nasal interface 232 in a manner so as to be translatable between different positions thereof. Accordingly, the at least one of the two or more electrical sensing elements may be operatively coupled to the headgear 234 and / or the nasal interface 232 in a manner so as to be freely movable relative to said headgear 234 and / or said nasal interface 232. In such a configuration, a position of the electrical sensing elements 252 may be adjusted or moved before and / or after the patient interface 230 is worn. Accordingly, depending on the size of the patient’s head, the electrical sensing elements 252 may be moved relative to the headgear 234 and / or the nasal interface 232 to be pre-positioned prior to being worn. Subsequently, when the patient interface 230 is worn, the position of the electrical sensing elements 252 may be moved or adjusted so as to be re-positioned relative to the patient’s head.

[0226] FIG. 9 shows a strip of two or more electrical sensing elements 252 being movably attached to the headgear 234 and / or the nasal interface 232. The electrical sensing elements 252 may be arranged in series to form the strip of electrical sensing elements 252. Further, the entire strip of electrical sensing elements 252, as a whole, may be attached to the headgear 234 or the nasal interface 232 in a manner so as to be movable relative to said headgear 234 or said nasal interface 232. According to various embodiments, the strip of electrical sensing elements 252 may be translatable in either or both directions along its longitudinal axis.

[0227] FIG. 10 shows an enlarged view of one of the electrical sensing elements 252 of FIG. 9. FIG. 1 1 shows an A-A sectional view of the electrical sensing element 252 of FIG. 10. While FIG. 10 and FIG. 11 shows one of the electrical sensing elements 252 of the strip of two or more electrical sensing elements 252 of FIG. 9, it is understood that, in other embodiments, the electrical sensing elements 252 may be separate and independent of each other, and may be independently movably attached to either the headgear 234 and / or the nasal interface 232. For example, as shown, according to various embodiments, each electrical sensing element 252 may be attached to a slide attachment 254f. The slide attachment 254f may be configured to be slidable relative to the headgear 234 and / or the nasal interface 232. For example, the slide attachment 254f may be slidable relative to a strap 258f of the headgear 234 or the nasal interface 232. Further, the slide attachment 254f may also be configured in a manner such that at least one electrical sensing element 252 may be attached thereto. Hence, the at least one electrical sensing element 252 may be attached or coupled to the slide attachment 254f. Therefore, the slide attachment 254f may serve to operatively couple the at least one electrical sensing element 252 to the strap 258f in a manner such that the at least one electrical sensing element 252 may be slidable along the strap 258f. According to various embodiments, the slide attachment 254f may include a slide channel 257. The strap 258f of the headgear 234 or the nasal interface 232 may be fitted through or inserted through the slide channel 257 of the slide attachment 254f such that the slide attachment 254f may be in sliding engagement with the strap 258f. Accordingly, the slide attachment 254f may be slidable relative to the strap 258f of the headgear 234 or the nasal interface 232 for moving the electrical sensing element 252 along the strap 258f of the headgear 234 or the nasal interface 232. Further, the slide attachment 254f may include a base portion 253a and a cap portion 253b defining the slide channel 257 therebetween. For example, the cap portion 253b may cover over an area of the base portion 253a in a manner so as to leave a space forming the slide channel 257 between the base portion 253a and the cap portion 253b. The base portion 253a may include an adhesive surface or a frictional surface. The adhesive surface or the frictional surface may be a surface 253aa of the base portion 253a (i.e. a patient facing side of the base portion 253a) opposite the surface 253ab of the base portion 253a (i.e. the outward facing side of the base portion 253a) with the cap potion 253b. The adhesive surface or the frictional surface may adhere the electrical sensing element 252 to the skin of thepatient so as to prevent the electrical sensing element 252 from moving relative to the patient’s head when the patient interface is worn. As an example, the electrical sensing element 252 may be disposed to the base portion 253a of the slide attachment 254f such that adhering the slide attachment 254f to the skin of the patient may adhere the electrical sensing element 252 to the skin of the patient. According to various embodiments, the slide attachments 254f of the electrical sensing elements 252 may be interconnected by link members 255 to form a strip. For example, the slide attachments 254f may be formed or joined together. As a further example, the slide attachments 254f may be integrally moulded together or integrally joined together. Accordingly, with the slide attachments 254f being interconnected, the electrical sensing elements as a whole may be translatable relative to the headgear 234 or the nasal interface 232.

[0228] Referring to FIG. 7, according to various embodiments, at least one of the two or more electrical sensing elements 252 may be removably attached to either one or both of the headgear 234 and the nasal interface 232. As shown, each end of the single attachment member 254d, with the electrical sensing elements 252 thereon, may include a removable connector 251 for connecting to the corresponding ends 259 of the strap 258d of the headgear 234 or the nasal interface 232 in a removable manner. Accordingly, the electrical sensing elements 252 may be removed from the strap 258d of the headgear 234 or the nasal interface 232 by decoupling or detaching the removable connector 251 from the correspond ends 259 of the strap 258d of the headgear 234 or the nasal interface 232.

[0229] Referring back to FIG. 1 and FIG. 2, according to various embodiments, the headgear 234 may include a head strap portion 262 that forms a continuous loop with the nasal interface 232. As shown, as an example, the headgear 234 may include only the head strap portion 262 forming the continuous loop with the nasal interface 232. In other words, the headgear 234 may include only one single head strap portion 262 (or consist essentially of the head strap portion 262) without other strap portions or cover portions. According to various embodiments, as described later, the headgear 234 may include the head strap portion 262, which forms the continuous loop with the nasal interface 232, as one portion of the headgear 234, and the headgear 234 may include other strap portions.

[0230] FIG. 12 to FIG. 15 show various other examples of patient interfaces 1230, 1330, 1430, 1530 (or patient interface assemblies), wherein the headgear 234 mayinclude only the head strap portion 262 to form the continuous loop with the nasal interface 232. As shown, the continuous loop formed by the head strap portion 262 and the nasal interface 232 may be an uninterrupted closed girdle for encircling or enclosing around the patient’s head. For example, when worn, the head strap portion 262 may go around the back of the patient’s head. Accordingly, the head strap portion 262 and the nasal interface 232 forming the continuous loop may make it easy to don and doff from the patient’s head.

[0231] According to various embodiments, the head strap portion 262 of the headgear 234 may extend from the first lateral portion 244 of the nasal interface 232 to the second lateral portion 246 of the nasal interface 232. Accordingly, a first segment of the head strap portion 262 may be joined to the first lateral portion 244 of the nasal interface 232, and a second segment of the head strap portion 262 may be joined to the second lateral portion 246 of the nasal interface 232. The portions may be removably, movably or permanently joined. According to various embodiments, the head strap portion 262 of the headgear 234 may be extending from the nasal interface 232 in a manner such that the continuous loop formed by the head strap portion 262 and the nasal interface 232 may lie in a single plane. Accordingly, the first segment of the head strap portion 262, the first lateral portion 244 of the nasal interface 232, the second segment of the head strap portion 262 and the second lateral portion 246 of the nasal interface 232 may lie in the same plane.

[0232] According to various embodiments, the two or more electrical sensing elements 252 of the electrical sensing arrangement 250 may be distributed along the continuous loop formed by the head strap portion 262 of the headgear 234 and the nasal interface 232. FIG. 2 shows an example of the patient interface 230 with the two or more electrical sensing elements 252 of the electrical sensing arrangement 250 distributed along the head strap portion 262 of the headgear 234 of the continuous loop. FIG. 12 shows an example of the patient interface 1230 with the two or more electrical sensing elements 252 of the electrical sensing arrangement 250 distributed along the nasal interface 232 of the continuous loop. FIG. 13 shows an example of the patient interface 1330 with the two or more electrical sensing elements 252 of the electrical sensing arrangement 250 distributed along both the head strap portion 262 of the headgear 234 and the nasal interface 232 of the continuous loop.

[0233] Referring to FIG. 2, FIG. 12 and FIG. 13, according to various embodiments, a distribution of the two or more electrical sensing elements 252 from the first lateralportion 244 of the nasal interface 232 to a mid-point of the head strap portion 262 of the headgear 234 may be symmetrical with a distribution of the two or more electrical sensing elements 252 from the second lateral portion 246 of the nasal interface 232 to the mid-point of the head strap portion 262 of the headgear 234. Accordingly, the two or more electrical sensing elements 252 may be symmetrically distributed along the continuous loop in two opposite directions from the mid-point of the head strap portion 262 of the headgear 234. Hence, the mid-point of the head strap portion 262 of the headgear 234 may be a reference point for dividing the continuous loop into two equal halves such that the distribution of the two or more electrical sensing elements 252 may be symmetrical between the two equal halves of the continuous loop. The distribution may involve equidistant spacing between electrical sensing elements 252, or non-equidistant spacing between electrical sensing elements 252. In some embodiments, the distribution of the two or more electrical sensing elements 252 is not symmetrical. For example, the two or more electrical sensing elements 252 may have a different distribution from the first lateral portion 244 of the nasal interface 232 than the distribution of the two or more electrical sensing elements 252 from the second lateral portion 255. In some embodiments, the number of electrical sensing elements distributed from the first lateral portion 244 of the nasal interface 232 is different to the number of electrical sensing elements distributed from the second lateral portion 246 of the nasal interface 232. In some embodiments, the two or more electrical sensing elements 252 may be distributed in a manner that places them at two or more different locations on the patient’s head, such locations including but not limited to the top of the head, forehead, nose, one or both sides of the head, one or both cheeks, the jaw, ear and the like.

[0234] For example, as shown in FIG. 2, the patient interface 230 may include three electrical sensing elements 252. A first of the three electrical sensing elements 252 may be disposed at the mid-point of the head strap portion 262 of the headgear 234. A second of the three electrical sensing elements 252 may be disposed along a segment of the head strap portion 262 of the headgear 234 extending from the first lateral region 244 of the nasal interface 232 to the mid-point of the head strap portion 262 of the headgear 234, and a third of the three electrical sensing elements 252 may be disposed along a segment of the head strap portion 262 of the headgear 234 extending from the second lateral region 246 of the nasal interface 232 to the midpoint of the head strap portion 262 of the headgear 234. Accordingly, the threeelectrical sensing elements 252 may be distributed in a symmetrical manner from both sides of the mid-point of the head strap portion 262 of the headgear 234.

[0235] As another example, as shown in FIG. 12, the patient interface 1230 may include four electrical sensing elements 252. Two of the four electrical sensing elements 252 may be distributed along the first lateral portion 244 of the nasal interface 232 and two other electrical sensing elements may be distributed along the second lateral portion 246 of the nasal interface 232. Accordingly, the distribution of the electrical sensing elements 252 from the first lateral portion 244 of the nasal interface 232 to the mid-point of the head strap portion 262 of the headgear 234 may be symmetrical with the distribution of the electrical sensing elements 252 from the second lateral portion 246 of the nasal interface 232 to the mid-point of the head strap portion 262 of the headgear 234.

[0236] As a further example, as shown in FIG. 13, the patient interface 1330 may include seven electrical sensing elements 252. A first of the seven electrical sensing elements 252 may be disposed at the mid-point of the head strap portion 262 of the headgear 234. A second of the seven electrical sensing elements 252 may be disposed along a segment of the head strap portion 262 of the headgear 234 extending from the first lateral region 244 of the nasal interface 232 to the mid-point of the head strap portion 262 of the headgear 234. A third of the seven electrical sensing elements 252 may be disposed along a segment of the head strap portion 262 of the headgear 234 extending from the second lateral region 246 of the nasal interface 232 to the mid-point of the head strap portion 262 of the headgear 234. A fourth and a fifth of the seven electrical sensing elements 252 may be distributed along the first lateral portion 244 of the nasal interface 232, and a sixth and a seventh of the seven electrical sensing elements may be distributed along the second lateral portion 246 of the nasal interface 232. Accordingly, the seven electrical sensing elements 252 may be distributed in a symmetrical manner from both sides of the mid-point of the head strap portion 262 of the headgear 234.

[0237] According to various embodiment, each of the two or more electrical sensing elements 252 of the electrical sensing arrangement 250 may be disposed along the continuous loop at a corresponding predetermined distance from a mid-point of the main portion 242 of the nasal interface 232. Accordingly, the mid-point of the main portion 242 of the nasal interface 232 may be used as a reference position for positioning of each of the two or more electrical sensing elements 252 along thecontinuous loop. For example, positions on the patient’s head for measuring of electrical activity may be selected with reference to a nasal reference point of a face of the patient (e.g., a base of the nose of the patient) and the main portion 242 of the nasal interface 232 may be configured to be placed or positioned at the nasal reference point of the face of the patient when the patient interface 230, 1230, 1330 is worn on the patient’s head. Accordingly, the selected position for measuring electrical activity with reference from the nasal reference point of the face of the patient may be transposed to the corresponding predetermined distance from the mid-point of the main portion 242 of the nasal interface 232 along the continuous loop of the patient interface 230, 1230, 1330. Therefore, by selecting the positions on the patient’s head for measuring of electrical activity with reference to the nasal reference point, the corresponding predetermined distance from the mid-point of the main portion 242 of the nasal interface 232 may be determined for disposing the two or more electrical sensing elements 252 of the electrical sensing arrangement 250.

[0238] Referring to FIG. 2, FIG. 12 and FIG. 13, according to various embodiments, the continuous loop formed by the head strap portion 262 of the headgear 234 and the nasal interface 232 may be configured to loop across a top region of the patient’s head. For example, when viewed from a side profile of the patient’s head, the continuous loop may stretch diagonally from the nose of the patient, over the ear of the patient and towards a back of the patient’s head that is above the ear (e.g., a crown of the patient’s head). Accordingly, the continuous loop formed by the head strap portion 262 of the headgear 234 and the nasal interface 232 may encircle the patient’s head from the nose to the top region of the patient’s head (e.g., a top-rear region of the patient’s head).

[0239] FIG. 14 and FIG. 15 show other examples of the patient interface 1430, 1530, wherein the head strap portion 262 of the headgear 234 forms a continuous loop with the nasal interface 232 and with the two or more electrical sensing elements 252 of the electrical sensing arrangement 250 distributed along the continuous loop. However, the two or more electrical sensing elements 252 may be suspended or hung from the continuous loop or may be supported or held up from the continuous loop.

[0240] For example, as shown in FIG. 14, the two or more electrical sensing elements 252 may hang from the continuous loop. In particular, one electrical sensing element 252 of the two or more electrical sensing elements 252 may be disposed along the continuous loop and the remaining electrical sensing elements 252 may be hangingdownwards from the one electrical sensing element 252. As shown, the patient interface 1430 may include four electrical sensing elements 252. One electrical sensing element 252 may be disposed at a mid-point of the head strap portion 262 of the headgear 234 and the remaining three electrical sensing elements 252 may be hanging vertically downward in series from the one electrical sensing element 252. In some examples, the two or more electrical sensing elements may be oriented non- vertically such as angled forward the patient’s left or right side.

[0241] As another example, as shown in FIG. 15, the two or more electrical sensing elements 252 may be held up from the continuous loop. In particular, one electrical sensing element 252 may disposed along the continuous loop and the remaining electrical sensing elements 252 may be held up from the one electrical sensing element 252. As shown, the patient interface 1530 may include four electrical sensing elements 252. One electrical sensing element 252 may be disposed along a segment of the head strap portion 262 of the headgear 234 adjacent to the first lateral portion 244 of the nasal interface 232, and the remaining three electrical sensing elements 252 may be held upwards in series from the one electrical sensing element 252. Further, the remaining three electrical sensing elements 252 may be arranged to curve towards a forehead of the patient.

[0242] FIG. 16 to FIG. 20 show various examples of patient interfaces 1630, 1730, 1830, 1930, 2030 (or patient interface assemblies), wherein the headgear 234 may include a network of straps 260. As shown, the network of straps 260 of the patient interface 1630, 1730, 1830, 1930, 2030 may include the head strap portion 262 forming the continuous loop with the nasal interface 232. Further, the network of straps 260 may include additional strap portion(s) in addition to the head strap portion 262.

[0243] As shown in FIG. 16, the network of straps 260 of the headgear 234 of the patient interface 1630 may include the head strap portion 262 and a chin strap portion 264. The chin strap portion 264 may be for wearing across a chin of the patient. Accordingly, the chin strap portion 264 may be extending below the nasal interface 232 so as to be wearable over and across the chin of the patient. In some embodiments, one or both of the head strap portion 262 and the chin strap portion 264 (or parts thereof) may be capable of stretching, and in some cases may have elasticity to provide some flexibility in the positioning of the respective strap portions and hence, the location of associated electric sensing elements, on the patient. In some embodiments, one or both of the head strap portion 262 and the chin strap portion 264may not be stretchable, but may be adjustable in length to accommodate different positioning. In some embodiments, one or more electric sensing elements may be movable relative to one or both of the head strap portion 262 and the chin strap portion 264 to provide the user with flexibility in the location of the electric sensing elements on the patient. According to various embodiments, the two or more electrical sensing elements 252 may be distributed along the chin strap portion 264 of the network of straps 260 of the headgear 234. As shown, the two or more electrical sensing elements 252 may be distributed along the chin strap portion 264 in a symmetrical manner with respect to a mid-point of the chin strap portion 264. For example, when there are five electrical sensing elements 252, one of the electrical sensing elements 252 may be disposed at the mid-point of the chin strap portion 264 with two electrical sensing elements 252 disposed along a first segment of the chin strap portion 264 extending in a first direction from the mid-point of the chin strap portion 264 and another two electrical sensing elements disposed along a second segment of the chin strap portion 264 extending in a second direction, opposite the first direction, from the mid-point of the chin strap portion 264.

[0244] As shown in FIG. 17, the network of straps 260 of the headgear 234 of the patient interface 1730 may include the head strap portion 262 and a forehead strap portion 266. The forehead strap portion 266 may be for wearing across a forehead of the patient. Accordingly, the forehead strap portion 266 may be extending above the nasal interface 232 so as to be wearable over and across the forehead of the patient. According to various embodiments, the two or more electrical sensing elements 252 may be distributed along the forehead strap portion 266 of the network of straps 260 of the headgear 234. As shown, the two or more electrical sensing elements 252 may be distributed along the forehead strap portion 266 in a symmetrical manner with respect to a mid-point of the forehead strap portion 266. For example, when there are three electrical sensing elements 252, a first of the electrical sensing elements 252 may be disposed at the mid-point of the forehead strap portion 266 with a second of the electrical sensing elements 252 disposed along a first segment of the forehead strap portion 266 extending in a first direction from the mid-point of the forehead strap portion 266 and a third of the electrical sensing elements disposed along a second segment of the forehead strap portion 266 extending in a second direction, opposite the first direction, from the mid-point of the forehead strap portion 266.

[0245] As shown in FIG. 18, the network of straps 260 of the headgear 234 of the patient interface 1830 may include the head strap portion 262, the chin strap portion 264 and the forehead strap portion 266. The chin strap portion 264 may be for wearing across a chin of the patient and the forehead strap portion 266 may be for wearing across a forehead of the patient. Accordingly, the chin strap portion 264 may be extending below the nasal interface 232 so as to be wearable over and across the chin of the patient and the forehead strap portion 266 may be extending above the nasal interface 232 so as to be wearable over and across the forehead of the patient. According to various embodiments, the two or more electrical sensing elements 252 may be distributed along the chin strap portion 264 and the forehead strap portion 266 of the network of straps 260 of the headgear 234. As shown, a distribution of the electrical sensing elements 252 along the chin strap portion 264 may be in a symmetrical manner with respect to the mid-point of the chin strap portion 264 and a distribution of the electrical sensing elements 252 along the forehead strap portion 266 may be in a symmetrical manner with respect to the mid-point of the forehead strap portion 266.

[0246] As shown in FIG. 19, the network of straps 260 of the headgear 234 of the patient interface 1930 may include the head strap portion 262, the chin strap portion 264, the forehead strap portion 266, an overhead strap portion 268 and a cheek strap portion 265. The chin strap portion 264 may be for wearing across a chin of the patient, the forehead strap portion 266 may be for wearing across a forehead of the patient, the overhead strap portion 268 may be for wearing over a top of the head of the patient, and the cheek strap portion 265 may be for wearing across both cheeks of the patient. Accordingly, the chin strap portion 264 may be extending below the nasal interface 232 so as to be wearable over and across the chin of the patient, the cheek strap portion 265 may be extending above the nasal interface 232 so as to be wearable across both cheeks of the patient, the forehead strap portion 266 may be extending above the cheek strap portion 265 so as to be wearable over and across the forehead of the patient, and the overhead strap portion 268 may be extending above the forehead strap portion 266 so as to be wearable over the top of the patient’s head. According to various embodiments, the two or more electrical sensing elements 252 may be distributed along the chin strap portion 264, the forehead strap portion 266, the cheek strap portion 265, and the overhead strap portion 268 of the network of straps 260 of the headgear 234. As shown, a distribution of the electrical sensingelements 252 along the chin strap portion 264 may be in a symmetrical manner with respect to the mid-point of the chin strap portion 264, a distribution of the electrical sensing elements 252 along the forehead strap portion 266 may be in a symmetrical manner with respect to the mid-point of the forehead strap portion 266, a distribution of the electrical sensing elements 252 along the cheek strap portion 265 may be in a symmetrical manner with respect to a mid-point of the cheek strap portion 265, and a distribution of the electrical sensing elements 252 along the overhead strap portion 268 may be in a symmetrical manner with respect to the mid-point of the overhead strap portion 268.

[0247] As shown in FIG. 20, the network of straps 260 of the headgear 234 of the patient interface 2030 may include the head strap portion 262 and an adjustable strap portion 270. The adjustable strap portion 270 may be adjustable to change between different positions for wearing over different regions of the patient’s head. For example, the adjustable strap portion 270 may be adjusted to a chin position below the nasal interface 232 for wearing across the chin of the subject or patient, to a forehead position above the nasal interface 232 for wearing across the forehead of the subject or patient, and to an overhead position for wearing over a top of the head of the subject or patient. According to various embodiments, the two or more electrical sensing elements 252 may be distributed along the adjustable strap portion 270 of the network of straps 260 of the headgear 234. As shown, the two or more electrical sensing elements 252 may be distributed along the adjustable strap portion 270 in a symmetrical manner with respect to a mid-point of the adjustable strap portion 270. With the adjustable strap portion 270 capable of being changed between different positions, the adjustable strap portion 270 may be adjusted to position the two or more electrical sensing elements 252 to desired positions of the patient’s head whereby electrical activity is to be detected and / or monitored.

[0248] Referring back to FIG. 16 to FIG. 20, according to various embodiments, the network of straps 260 of the headgear 234 of the patient interface 1630, 1730, 1830, 1930, 2030 may include a pair of nodes 261 , 263 respectively at two opposite lateral portions of the headgear 234 (e.g., a first lateral portion and a second lateral portion of the headgear 234). The nasal interface 232 may be at an anterior position of the headgear 234 and the two opposite lateral portions of the headgear 234 may correspond to a left portion and a right portion of the headgear 234 with respect to the nasal interface 232. Accordingly, the two opposite lateral portions of the headgear 234may be portions of the headgear 234 respectively to the left and to the right of the nasal interface 232. Hence, the nasal interface 232 may be between the two opposite lateral portions of the headgear 234.

[0249] According to various embodiments, with the pair of nodes 261 , 263 of the headgear 234, the network of straps 260 may include one or more strap portions extending between the pair of nodes 261 , 263 to form the headgear 234. For example, the head strap portion 262 may extend between the pair of nodes 261 , 263 (for example, see FIG. 16 to FIG. 20), and / or the chin strap portion 264 may extend between the pair of nodes 261 , 263 (for example, see FIG. 16, FIG. 18, and FIG. 19), and / or the forehead strap portion 266 may extend between the pair of nodes 261 , 263 (for example, see FIG. 17 to FIG. 19), and / or the overhead strap portion 268 may extend between the pair of nodes 261 , 263 (for example, see FIG. 19), and / or the adjustable strap portion 270 may extend between the pair of nodes 261 , 263 (for example, see FIG. 20).

[0250] According to various embodiments, when the patient interface 1630, 1730, 1830, 1930, 2030 is worn, each of the pair of nodes 261 , 263 of the headgear 234 may be positioned at an area in front of a corresponding ear of the patient (i.e., a preauricular region of the face of the patient). Accordingly, the nasal interface 232 may be positioned at the nose of the patient and the pair of nodes 261 , 263 may be respectively positioned in front of both ears of the patient when the headgear 234 is worn.

[0251] According to various embodiments, the headgear 234 having the network of straps 260 with the pair of nodes 261 , 263 may improve usability, enhance ease of wearing with reduced number of steps for user to position both the nasal interface 232 and the two or more electrical sensing elements 252, as well as allow multiple placement of the two or more electrical sensing elements 252 across different parts of the patient’s head in a clean and sleek manner to minimally obstruct access to regions of the patient’s face.

[0252] As shown in FIG. 16 to FIG. 20, according to various embodiments, the first lateral portion 244 of the nasal interface 232 may extend from the main portion 242 of the nasal interface 232 to a first node 261 of the pair of nodes 261 , 263 and directly join to the first node 261 of the pair of nodes 261 , 263. Similarly, the second lateral portion 246 of the nasal interface 232 may extend from the main portion 242 of the nasal interface 232 to a second node 263 of the pair of nodes 261 , 263 and directlyjoin to the second node 263 of the pair of nodes 261 , 263. However, it is understood that, according to various embodiments, the network of straps 260 may include a first strap segment extending from the first node 261 of the pair of nodes 261 , 263 to the first lateral portion 244 of the nasal interface 232 and a second strap segment extending from the second node 263 of the pair of nodes 261 , 263 to the second lateral portion 246 of the nasal interface 232. Therefore, the first lateral portion 244 of the nasal interface 232 may either be directly joined to the first node 261 of the pair of nodes 261 , 263, or be joined to the first node 261 via the first strap segment, and the second lateral portion 246 of the nasal interface 232 may either be directly joined to the second node 263 of the pair of nodes 261 , 263, or be joined to the second node 263 via the second strap segment.

[0253] According to various embodiments, the headgear 234 of the patient interface 230, 1230, 1330, 1430, 1530, 1630, 1730, 1830, 1930, 2030, may be conformable to the patient’s head for wearing on the patient’s head. Accordingly, the headgear 234 may be adjustable or deformable to fit in a conforming manner over the patient’s head. Hence, when worn on the patient’s head, the headgear 234 may follow or comply with the contours of the patient’s head closely. With the headgear 234 being conformable to the patient’s head, the headgear 234 may be worn securely over the patient’s head.

[0254] According to various embodiments, when the headgear 234 is worn on the patient’s head, the nasal interface 232 may be retained, by the headgear 234, to bear against the upper lip and / or nose of the patient along an interface vector (or a predetermined force vector along which the nasal interface 232 is acting on the upper lip and / or nose of the patient), and at least one electrical sensing element 252 of the electrical sensing arrangement 250 may be retained, by the headgear 234, to bear against a corresponding position of the patient’s head along an electrode vector (or a predetermined force vector along which the at least one electrical sensing element 252 is acting on the corresponding position of the patient’s head) directed in a predetermined direction towards the corresponding position of the patient’s head. With the nasal interface 232 held by the headgear 234 to bear against the upper lip and / or nose of the patient along the interface vector, the nasal interface 232 may be maintained in a position and an orientation to deliver consistent gas flow into the nose of the patient in a manner so as to minimise movement of the nasal interface 232 that would disrupt the delivery of gases flow into the nose of the patient. With the electrode vector of the at least one electrical sensing element 252 directed in the predetermineddirection towards the corresponding position of the patient’s head, the at least one electrical sensing element 252 may maximise contact with the corresponding position of the patient’s head for enhancing the reliability and quality of a detection signal of the at least one electrical sensing element 252. Accordingly, the headgear 234 may conform to the patient’s head in a manner to retain the nasal interface 232 in the position and the orientation to minimise or avoid disruption of the delivery of gases flow into the nose of the patient, and, concurrently, retain the at least one electrical sensing elements 252 of the electrical arrangement 250 with the at least one electrical sensing element 252 being positioned and oriented to enhance the reliability and quality of the detection signal of the at least one electrical sensing element 252.

[0255] According to various embodiments, when the headgear 234 is worn on the patient’s head, the nasal interface 232 may be retained by the headgear 234 with the main portion 242 of the nasal interface 232 bearing against the nose of the patient, e.g., the upper lip and / or the columella base of the nose and / or the philtrum under the nose, along the interface vector. Further, the at least one nasal delivery elements 348 (e.g., in the form of the nasal prong) extending from the main portion 242 of the nasal interface 232 may be loosely inserted or fitted or positioned into a corresponding nare of the nose of the patient. Accordingly, the main portion 242 of the nasal interface 232 may be exerting a force along the interface vector on the nose of the patient to keep the nasal interface 232 in place with respect to the nose of the patient, while the at least one nasal delivery elements 348 may be merely introduced into the corresponding nare of the nose without exerting any force on the nare of the nose for keeping the nasal interface 232 in place with respect to the nose. Hence, the main portion 242 of the nasal interface 232 may be retained by the headgear 234 in a position to interact with the nose of the patient for applying a retaining force (i.e. the force along the interface vector) against the nose to keep the nasal interface 232 in place and in an orientation to introduce the at least one nasal delivery elements into the corresponding nare of the nose without causing the at least one nasal delivery elements to apply any force contributing to the retention of the nasal interface 232 with respect to the nose of the patient.

[0256] FIG. 21 shows the interface vector with respect to the nose of the patient for keeping the nasal interface 232 in place according to the various embodiments. As shown, the interface vector may extend from the columella base of the nose of the patient and may be directed into the face of the patient between an angle normal to asurface of the columella base (or normal to a line from the nasal tip to the nasal base, or normal to an inferior margin of the septum of the nose) and an angle normal to a surface of the upper lip, e.g. the philtrum, (or normal to a line extending from the nasal base to a border of the upper lip). Accordingly, the interface vector may be extending from the columella base of the nose of the patient to form an angle with a transverse plane of the patient’s head and may be angled or directed towards the coronal plane of the patient’s head. According to various embodiments, the angle between the interface vector and the transverse plane may be between 0° and 90°. According to various embodiments, the interface vector may be resolved into a horizontal component lying along the transverse plane of the patient’s head and directed perpendicularly towards the coronal plane of the patient’s head, and a vertical component extending perpendicularly upwards from the transverse plane of the patient’s head.

[0257] FIG. 22 shows the electrode vector of at least one electrical sensing element 252 according to various embodiments. According to various embodiments, when the headgear 234 is worn on the patient’s head, at least one electrical sensing element 252 of the electrical sensing arrangement 250 may be retained by the headgear 234 and / or the adhesive / frictional surface of the at least one electrical sensing element 252 and / or the adhesive / frictional surface of the attachment member 254a, 254b, 254c, 254d / slide attachment member 254f in an orientation with the electrode vector of the at least one electrical sensing element 252 directed in the predetermined direction towards the corresponding position of the patient’s head. As shown, the predetermined direction of the electrode vector of the at least one of the two or more electrical sensing elements may be directed substantially perpendicular towards the corresponding position of the patient’s head. Accordingly, the predetermined direction may be perpendicular to a tangent of the corresponding position of the patient’s head or may be an inward pointing normal of the corresponding position of the patient’s head. Thus, at least one electrical sensing element 252 may apply a force perpendicular to the surface of the corresponding position of the patient’s head. In this manner, the at least one electrical sensing element 252 may maximise contact with the corresponding position of the patient’s head such that the reliability and quality of a detection signal of the at least one electrical sensing element 252 may be optimised.

[0258] According to various embodiments, the headgear 234 may be capable of being worn or donned with minimal effort to achieve placement of the nasal interface 232and the two or more electrical sensing element 252 such that the nasal interface 232 may bear against the nose of the patient along the interface vector and at least one electrical sensing element 252 of the electrical sensing arrangement 250 may bear against the corresponding position of the patient’s head with the electrode vector of the at least one electrical sensing element 252 directed in the predetermined direction. Accordingly, the headgear 234 may be configured to be wearable with minimal (e.g., one) motion to place the nasal interface 232 for bearing against the nose of the patient along the interface vector and to place the at least one electrical sensing element 252 for bearing against the corresponding position of the patient’s head with the electrode vector of the at least one electrical sensing element directed in the predetermined direction.

[0259] According to various embodiments, as the headgear 234 is conforming to the patient’s head for fitting thereon via adjustment or deformation, the headgear 234 may be tightened accordingly. Tightening of the headgear may increase a magnitude of the force along the interface vector exerted by the nasal interface 232 and / or a force along the electrode vector exerted by at least one electrical sensing element 252 simultaneously. This may in turn increase stability of the nasal interface 232 from accidental movements, and enhance the reliability and quality of the signal from the at least one electrical sensing element 252 due to increased skin contact.

[0260] According to various embodiments, the headgear 234 may be resilient and may have a natural tendency to return to a contracted state. Accordingly, the headgear 234 may be manipulated into an expanded state for placing over the patient’s head. Upon releasing the headgear 234 on the patient’s head, the headgear 234 may be inclined to return from the expanded state to the contracted state, and in the process may conform the headgear 234 to the patient’s head. When the headgear 234 is in the contracted state, the headgear 234 may not have returned fully to the contracted state and may be under tension to maintain the headgear 234 on the patient’s head so as to secure the headgear 234 to the patient’s head. Accordingly, the resilience of the headgear 234 may enable the headgear 234 to tighten for conforming to the patient’s head as the headgear 234 returns to the contracted state, and the tightening of the headgear 234 may increase the force exerted by the nasal interface 232 and the force exerted by the at least one electrical sensing element 252. Hence, the resilience of the headgear 234 may facilitate wearing of the headgear 234 as well asmaintaining the nasal interface 232 and the at least one electrical sensing element 252 in their respective positions and / or orientations.

[0261] According to various embodiments, the headgear 234 may include an elastic material. The elastic material may be stretchable to be conformable to the patient’s head or to conform the headgear 234 to the patient’s head. Accordingly, the elastic material may be deformable to enable the headgear 234 to be stretched and widened, by a widening force, into the expanded state for placing over the patient’s head. Upon placing the headgear 234 over the patient’s head, the widening force may be removed to release the headgear 234 onto the patient’s head. The elastic material may then start to return to the contracted state. In the process, an elastic force of the elastic material may cause the headgear 234 to tighten over the patient’s head and conform to the patient’s head. When the headgear 234 is conformed to the patient’s head, the elastic material may not have fully return to the contracted state and may continue to apply the elastic force to maintain the headgear 234 in tension over the patient’s head so as to secure the headgear 234 to the patient’s head. Accordingly, the elastic material may enable the headgear 234 to conform to the patient’s head for wearing and may provide the elastic force for keeping the nasal interface 232 and the at least one electrical sensing element 252 in place. Hence, the elastic force of elastic material of the headgear 234 may facilitate wearing of the headgear 234 as well as maintaining the nasal interface 232 and the at least one electrical sensing element 252 in their respective positions and / or orientations.

[0262] According to various embodiments, the headgear 234 may include an adjustable arrangement 272 (for example see FIG. 24, FIG. 26 and FIG. 27) to tighten the headgear 234 for conforming to the patient’s head. According to various embodiments, the adjustable arrangement 272 may be operable to tighten the headgear 234 so as to conform to the patient’s head. The adjustable arrangement 272 may be operable to loosen and widen the headgear 234 into the expanded state for placing over the patient’s head. Upon placing the headgear 234 over the patient’s head, the adjustable arrangement 272 may be operable to tighten the headgear 234 so as to contract the headgear 234 for conforming to the patient’s head. When the headgear 234 is conformed to the patient’s head, the adjustable arrangement 272 may be further operated to tighten the headgear 234 in a manner such that the headgear 234 may be under tension. With the headgear 234 being under tension, the tension may maintain the headgear 234 secured to the patient’s head. Further, the tension may translate tothe force exerted by the nasal interface 232 and the force exerted by the at least one electrical sensing element 252. Accordingly, tightening of the headgear 234 via the adjustable arrangement 272 may facilitate wearing of the headgear 234 as well as maintaining the nasal interface 232 and the at least one electrical sensing element 252 in their respective positions and / or orientations. According to various embodiments, the adjustable arrangement may include one or more or a combination of a ring, a slide, a hook, a buckle, a strap adjuster, or any suitable elements for adjusting one or more straps of the headgear 234.

[0263] FIG. 23 and FIG. 25 show a right side view and a left side view respectively of an example of a patient interface 2330 (or a patient interface assembly) having an adjustable arrangement 272 according to various embodiments. FIG. 24 shows an enlarged view of a first member 2372 of the adjustable arrangement 272 of the patient interface 2330 according to various embodiments. FIG. 26 shows an enlarged view of a second member 2572 of the adjustable arrangement 272 of the patient interface 2330 according to various embodiments. As shown, the adjustable arrangement 272 of the patient interface 2330 may include the first member 2372 and the second member 2572 respectively disposed on the right side and the left side of the headgear 234, or vice versa.

[0264] As shown, the first member 2372 may be a strap re-director and the second member 2572 may be a buckle. As also shown, the headgear 234 may include the head strap portion 262 and the forehead strap portion 266. The head strap portion 262 and the forehead strap portion 266 may be part of a single continuous strap. In other words, the single continuous strap may be looped around the patient’s head to form the head strap portion 262 and the forehead strap portion 266.

[0265] As shown, the single continuous strap may be strung through the first member 2372 (i.e. the strap re-director) such that a first portion of the single continuous strap and a second portion of the single continuous strap may form an angle with each other. Accordingly, the first portion of the continuous strap may serve as the head strap portion 262 and the second portion of the continuous strap may serve as the forehead strap portion 266. According to various embodiments, the first member 2372 (i.e. the strap re-director) may be configured to change a direction of the single continuous strap such that the first portion of the continuous strap and the second portion of the continuous strap may form the angle with respect to each other. For example, the first member 2372 (i.e. the strap re-director) may include a first rung and a second rungarranged at an angle with respect to each other such that the single continuous strap may go over the first rung and go under a second rung and fold over the second rung in order to change the direction of the single continuous strap.

[0266] As shown, a first end of the single continuous strap at an end of the head strap portion 262 and a second end of the single continuous strap at an end of the forehead strap portion 266 may be respectively strung through the second member 2572 (i.e. the buckle) at an angle with respect to each other. For example, the second member 2572 (i.e. the buckle) may include a first set of parallel slots and rungs arrangement for receiving the first end of the single continuous strap and a second set of parallel slots and rungs arrangement for receiving the second end of the single continuous strap. The first set of parallel slots and rungs and the second set of parallel slots and rungs may be angled from each other. Accordingly, shortening or lengthening either ends of the continuous strap with respect to the second member 2572 (i.e. the buckle) may simultaneously tighten or loosen the head strap portion 262 and the forehead strap portion 266. As further shown, the second member 2572 (i.e. the buckle) may include an engagement element 2574 for engaging with a corresponding engagement element at the nasal interface 232 to releasably attach to the nasal interface 232. The engagement element 2574 may include a releasably attachable element including, but not limited to, a quick-release clip, a quick release catch or a quick release latch. Accordingly, the engagement element 2574 and the corresponding engagement may form a quick release connection.

[0267] With the first member 2372 of the adjustable arrangement 272 being the strap re-director and the second member 2572 of the adjustable arrangement 272 being the buckle, the single continuous strap may stretch or extend from the second member 2572 (i.e. the buckle) loop across the forehead of the patient to form the forehead strap portion 266, strung through the first member 2372 (i.e. the strap re-director) to change a direction of the strap for looping around the back of the patient’s head to form the head strap portion 262, and return to the second member 2572 (i.e. the buckle). Further, adjustment of a tautness of the headgear 234 may be achieved by pulling either ends of the single continuous strap at the second member 2572 of the adjustable arrangement 272.

[0268] According to a variation of the embodiment as shown in FIG.23 to FIG. 26, each of the head strap portion 262 and the forehead strap portion 266 may be a separate and independent strap. In such an embodiment, the adjustable arrangement272 may include two buckles (similar to the second member 2572 as shown in FIG. 26) respectively disposed on the right side and the left side of the headgear 234. Accordingly, a first end of the head strap portion 262 may be strung through a first buckle and a second end of the head strap portion 262 may be strung through a second buckle. Similarly, a first end of the forehead strap portion 266 may be strung through the first buckle and a second end of the forehead strap portion 266 may be strung through the second buckle. Therefore, each of the head strap portion 262 and the forehead strap portion 266 may be independently tightened or loosened by respectively adjusting the ends thereof with respect to the corresponding buckles.

[0269] In some embodiments, one or more strap portions may be adjustable. FIG. 27 shows an example of the adjustable arrangement 272 according to various embodiments. According to various embodiments, the adjustable arrangement 272 may include a slide adjuster 2772. As shown, the slide adjuster 2772 is disposed along the head strap portion 262. However, it is understood that in other embodiments, the slide adjuster 2772 may be disposed along any one or more of the strap portions, e.g., the head strap portion 262, the chin strap portion 264, the forehead strap portion 266, the overhead strap portion 268, the adjustable strap portion 270. The slide adjuster 2772 may be operable to shorten or lengthen a corresponding strap portion for adjusting a tautness of the headgear 234. For example, when the slide adjuster 2772 is along the head strap portion 262 and the headgear 234 further includes any one or more of the other strap portions (e.g. the chin strap portion 264, the forehead strap portion 266, the overhead strap portion 268 and / or the adjustable strap portion 270), adjusting a length of the head strap portion 262 may simultaneously adjust the tautness of the head strap portion 262 and the one or more other strap portions so as to adjust the tautness of the headgear 234 as a whole. As shown in FIG. 27, the head strap portion 262 may include two separate and independent straps aligned to each other such that an end of each strap is connected to the slide adjuster 2772. Each of two separate and independent straps of the head strap portion 262 may be independently tightened or loosened by respectively adjusting the ends thereof with respect to the slide adjuster 2772. According to a variation, the head strap portion 262 may be a single independent strap. Accordingly, the slide adjuster 2772 may slidably couple an end of the single independent strap to a body of the single independent strap such that sliding the slide adjuster 2772 may vary an overall length of the head strap portion 262 for adjusting the tautness of the headgear 234.

[0270] FIG. 28 to FIG. 30 shows various examples of the headgear 234 according to various embodiments. FIG. 28 shows a patient interface 2830 (or a patient interface assembly) with the headgear 234 having the head strap portion 262 and the forehead strap portion 266, whereby the forehead strap portion 266 joins the head strap portion 262 at a position above the ear of the patient, instead of in front of the ear of the patient as shown in FIG. 17, FIG. 18 and FIG. 19. FIG. 29 shows a patient interface 2930 (or a patient interface assembly) with the headgear 234 having the forehead strap portion 266 and a flexible support member 2967. Two upper corners of the flexible support member 2967 may be respectively joined to two ends of the forehead strap portion 266 and two lower corners of the flexible support member 2967 may be respectively joined to the first lateral portion 244 and the second lateral portion 246 of the nasal interface 232. When worn, the two upper corners of the flexible support member 2967 may respectively extend above both ears of the patient, and the two lower corners of the flexible support member 2967 may respectively extend below both ears of the patient. FIG. 30 shows a patient interface 3030 (or a patient interface assembly) with the headgear 234 having the forehead strap portion 266 and a criss-cross portion 3069. Two upper legs of the criss-cross portion 3069 may be respectively joined to the forehead strap portion 266 and two lower legs of the criss-cross portion 3069 may respectively joined to the first lateral portion 244 and the second lateral portion 246 of the nasal interface 232. When worn, the two upper legs of the criss-cross portion 3069 may respectively extend above both ears of the patient, and the two lower legs of the criss-cross portion 3069 may respectively extend below both ears of the patient with the crossover located to the rear of the patient’s head. In some embodiments, the criss-cross portion 3069 or part thereof may be stretchable such as elastic, and / or adjustable in length and / or made from a breathable material. In some embodiments, the criss-cross portion 3069 may be made from a material which is the same as or which is different from forehead strap portion 266 of the headgear 234,

[0271] FIG. 31 and FIG. 32 show patient interfaces 3130, 3230 (or patient interface assemblies) with the headgear 234 including a nasal strap portion 276 according to various embodiments. The nasal strap portion 276 may be for wearing over a nose bridge of the patient. According to various embodiments, the nasal strap portion 276 may extend above the nasal interface 232 so as to be wearable over the nose bridge of the patient when the nasal interface 232 is bearing against the nose of the patient, e.g., the columella base of the nose and / or the philtrum under the nose. As shown inFIG. 31 , the patient interface 3130 may include the headgear 234 retaining the nasal interface 232, wherein the headgear 234 may include the head strap portion 262 and the nasal strap portion 276. The nasal strap portion 276 may extend from the first lateral portion 244 of the nasal interface 232 to the second lateral portion 246 of the nasal interface 232. As shown in FIG. 32, the patient interface 3230 may include the headgear 234 having only the nasal strap portion 276 without the head strap portion 262. Similarly, the nasal strap portion 276 may extend from the first lateral portion 244 of the nasal interface 232 to the second lateral portion 246 of the nasal interface 232.

[0272] According to various embodiments, the nasal strap portion 276 may be configured to maintain the nasal interface 232 in place when worn. Accordingly, when worn, the nasal strap portion 276 may be positioned and oriented to cause the nasal strap portion 276 to bear against the nose bridge of the patient as well as cause the nasal interface 232 to bear against the nose of the patient from below. Hence, the nasal strap portion 276 and the nasal interface 232 may cooperatively keep the nasal interface 232 in place. According to various embodiments, the nasal strap portion 276 may be of a predetermined length. The predetermined length may be based on the size and dimension of the nose of the patient. For example, the predetermined length of the nasal strap portion 276 may be a length that may cause the nasal strap portion 276 to lay across the nose bridge of the patient when worn for keeping the nasal interface 232 in place. As another example, the nasal strap portion 276 may include adhesion surfaces and / or frictional surfaces to secure or anchor the nasal strap portion 276 to the nose bridge of the patient for keeping the nasal interface 232 in place. Accordingly, the adhesion surfaces and / or friction surfaces of the nasal strap portion 276 may be in contact with the skin at the nose bridge region of the patient and may cause the nasal strap portion 276 to be stuck to the nose bridge of the patient.

[0273] FIG. 33 shows a sequence for wearing the nasal strap portion 276 and the nasal interface 232 on the nose of the patient. As shown, the nasal interface 232 may be placed against the nose of the patient, e.g., the columella base of the nose and / or the philtrum under the nose. The nasal strap portion 276 may then be pulled over the nose bridge of the patient. The nasal interface 232 may be rotated as the nasal strap portion 276 is being pulled over the nose bridge of the patient. When the nasal interface 232 is rotated to the desired orientation and the nasal strap portion 276 is at a desired position above the nose bridge of the patient, the nasal strap portion 276 may be released such that the nasal strap portion 276 and the nasal interface 232 may fit overthe nose in a manner to keep the nasal interface 232 in place. As previously mentioned, the nasal strap portion 276 may be of a predetermined length and / or have the adhesion surfaces and / or friction surfaces for maintaining the position and orientation of the nasal strap portion 276 so as to keep the nasal interface 232 in place.

[0274] According to various embodiments, the nasal strap portion 276 may be configured to apply a countering force to resist a load on one or more sides of the nasal interface 232. FIG. 34 shows a load 3436 acting on one side of the nasal interface 232. The load 3436 may be caused by a weight of a tube connected to the nasal interface 232 from that side of the nasal interface 232. The load 3436 may induce a moment on the nasal interface 232 and may cause the nasal interface 232 to rotate. When worn, the nasal strap portion 276 may counter the load 3436 and prevent the nasal interface 232 from movement or rotation. For example, with the adhesion surfaces and / or the frictional surfaces, the nasal strap portion 276 may be secured or anchored to the nose bridge of the patient in a manner so as to resist the moment acting on the nasal interface 232 as a result of the load 3436. As another example, in FIG. 31 , the head strap portion 262 may also provide additional resistance against the load 3436 from moving or rotating the nasal interface 232. Accordingly, in addition to the nasal strap portion 276, the headgear 234 may include one or more or a combination of the head strap portion 262, the chin strap portion 264, the forehead strap portion 266, the overhead strap portion 268, of any other suitable strap portion to jointly resist the load 3436 from moving or rotating the nasal interface 232.

[0275] As shown in FIG. 31 to FIG. 34, according to various embodiments, at least one of the two or more electrical sensing elements 252 of the electrical sensing arrangement 250 may be disposed at the nasal strap portion 276 of headgear 234. The at least one electrical sensing element 252 may include the adhesive surface or the frictional surface for providing additional resistance against the load 3436. The at least one electrical sensing element 252 may also be incorporated to the attachment member 254a, 254c or the elongated attachment member 254b, 254d having the adhesive surface or the frictional surface for providing the additional resistance against the load 3436.

[0276] According to various embodiments, a disposition of the at least one electrical sensing element 252 and the nasal strap portion 276 may be configured to apply the countering force to resist the load 3436 on one or more sides of the nasal interface 232. Accordingly, placement and positioning of the at least one electrical sensingelement 252, as well as orientation of the at least one electrical sensing element 252 may be selected such that the at least one electrical sensing element 252 and the nasal strap portion 276 may cooperatively resist the load 3436 so as to maintain the nasal interface 232 in place without being moved and / or rotated by the load 3436. Furthermore, a number of electrical sensing element 252 may also be placed to counter the load 3436 on the one or more sides of the nasal interface 232.

[0277] According to various embodiments, the nasal strap portion 276 of the headgear 234 may be conformable to the nose bridge of the patient for wearing on the nose bridge of the patient. Accordingly, the nasal strap portion 276 may be adjustable or deformable to fit in a conforming manner over the nose bridge of the patient. With the nasal strap portion 276 being conformable to the nose bridge of the patient, the nasal strap portion 276 may be worn securely over the nose of the patient.

[0278] According to various embodiments, when the nasal strap portion 276 is worn, the nasal interface 232 may be retained, by the nasal strap portion 276 and / or the at least one electrical sensing element 252, to bear against the nose of the patient along the interface vector. For example, the nasal interface 232 may be held in the desired position and / or orientation for delivering gases flow into the nose of the patient as a result of the at least one electrical sensing element 252 adhering to a corresponding position of the nose bridge of the patient. In this regard, the at least one electrical sensing element 252 may be positioned and / or oriented to face the nose bridge of the patient and may bear against a skin surface of a corresponding position of the nose bridge of the patient to apply a retention force (for example, perpendicularly) to the skin surface of the corresponding position of the nose bridge of the patient so as to be stuck to the skin surface of the corresponding position of the nose bridge of the patient for securing or anchoring the nasal strap portion 276 to the nose bridge of the patient in order to keep the nasal interface 232 in place. According to various embodiments, the at least one electrical sensing element 252 of the electrical sensing arrangement 250 may be retained, by the nasal strap portion 276, to bear against the corresponding position of the nose bridge of the patient with the electrode vector of the at least one electrical sensing element 252 directed in a predetermined direction towards the corresponding position of the nose bridge of the patient. With the nasal interface 232 held by the nasal strap portion 276 to bear against the nose of the patient along the interface vector, the nasal interface 232 may be maintained in a position and an orientation to deliver consistent gases flow into the nose of the patient in a manner soas to minimise movement of the nasal interface 232 that would disrupt the delivery of gases flow into the nose of the patient. With the electrode vector of the at least one electrical sensing element 252 directed in the predetermined direction towards the corresponding position of the nose bridge of the patient, the reliability and quality of a detection signal of the at least one electrical sensing element 252 may be enhanced. Accordingly, the nasal strap portion 276 may conform to the nose bridge of the patient in a manner to cause the at least one electrical sensing element 252 to adhere to the nose bridge of the patient such that the nasal interface 232 may be retained in the position and the orientation to minimise or avoid disruption of the delivery of gases flow into the nose of the patient, and, concurrently, the electrode vector of the at least one electrical sensing element 252 may be optimised to enhance the reliability and quality of the detection signal of the at least one electrical sensing element 252.

[0279] According to various embodiments, when the nasal strap portion 276 is worn on the nose bridge of the patient, the nasal interface 232 may be retained, by the nasal strap portion 276 and / or the at least one electrical sensing element 252, with the main portion 242 of the nasal interface 232 bearing against the nose of the patient, e.g., the columella base of the nose and / or the philtrum under the nose, along the interface vector. Further, the at least one nasal delivery elements 348 (e.g., in the form of the nasal prong) extending from the main portion 242 of the nasal interface 232 may be loosely inserted or fitted or positioned into the corresponding nare of the nose of the patient. Accordingly, the main portion 242 of the nasal interface 232 may be exerting a force along the interface vector on the nose of the patient to keep the nasal interface 232 in place with respect to the nose of the patient, while the at least one nasal delivery elements 348 may be merely introduced into the corresponding nare of the nose without exerting any force on the nare of the nose for keeping the nasal interface 232 in place with respect to the nose. Hence, the main portion 242 of the nasal interface 232 may be retained, by the nasal strap portion 276 and / or the at least one electrical sensing element 252, in a position to interact with the nose of the patient for applying a retaining force (i.e. the force along the interface vector) against the nose to keep the nasal interface 232 in place and in an orientation to introduce the at least one nasal delivery elements into the corresponding nare of the nose without causing the at least one nasal delivery elements to apply any force contributing to the retention of the nasal interface 232 with respect to the nose of the patient.

[0280] FIG. 35 to FIG. 37 show patient interfaces 3530, 3630, 3730 (or patient interface assemblies) with the headgear 234 including an ear strap portion 278 according to various embodiments. The ear strap portion 278 may be for wearing around an ear of the patient. According to various embodiments, the ear strap portion 278 may be extending laterally from the nasal interface 232 so as to be wearable around the ear of the patient when the nasal interface 232 is bearing against the nose of the patient, e.g., the columella base of the nose and / or the philtrum under the nose. As shown in FIG. 35, the patient interface 3530 may include the headgear 234 including a first ear strap portion 278a extending from the first lateral portion 244 of the nasal interface 232 and a second ear strap portion 278b extending from the second lateral portion 246 of the nasal interface 232. As shown in FIG. 36 and FIG. 37, the patient interfaces 3630, 3730 may include the headgear 234 including the forehead strap portion 266 and the ear strap portion 278. In FIG. 36, the ear strap portion 278 may be connected between the nasal interface 232 and the forehead strap portion 266 such that the nasal interface 232 and the forehead strap portion 266 may be free of any direct connection. On the other hand, in FIG. 37, the ear strap portion 278, the forehead strap portion 266 and the nasal interface 232 are connected together at a node (e.g., node 261 and / or node 263).

[0281] FIG. 38 shows a patient interface 3830 (or a patient interface assembly) having the nasal interface 232 with the two or more electrical sensing elements 252. While the patient interface 3830 of FIG. 38 is illustrated without any headgear 234, it is understood that the nasal interface 232 of FIG. 38 may be combined with any headgear 234 to form various patient interfaces according to the various embodiments disclosed herein. It is also understood that the nasal interface 232 of FIG. 38 may be standalone and independent without any headgear 234 to form the patient interface 3830 as shown in FIG. 38. According to various embodiments, the nasal interface 232 as shown in FIG. 38 may include at least one electrical sensing element 252 disposed at the first lateral portion 244 of the nasal interface 232 and at least one further electrical sensing element 252 disposed at the second lateral portion 246 of the nasal interface 232. The first lateral portion 244 and the second lateral portion 246 may be sized and shaped for positioning the respective electrical sensing element 252 at desired locations on the face of the patient when the main portion 242 of the nasal interface 232 is bearing against the nose of the patient, e.g., the columella base of the nose and / or the philtrum under the nose. For example, when the desired location forthe respective electrical sensing element 252 is at the cheek of the patient, the first lateral portion 244 and the second lateral portion 246 may respectively extend from the main portion 242 of the nasal interface 232 with a predetermined length and angle from the main portion 242 based on the location of the cheek of the patient from the columella base of the nose of the patient. Therefore, each of the first lateral portion 244 and the second lateral portion 246 may be configured accordingly based on desired placement location of the respective electrical sensing element 252. According to various embodiments, when the desired placement locations of the respective electrical sensing elements 252 are symmetrical across a sagittal plane of the patient’s head, the first lateral portion 244 and the second lateral portion 246 may extend in a symmetrical manner from the main portion 242 with respect to the sagittal plane of the patient’s head. According to various embodiments, when the desired placement locations of the electrical sensing elements on a left side of the face of the patient and the right side of the face of the patient are not symmetrical, i.e., different locations on respective side of the face of the patient, the first lateral portion 244 and the second lateral portion 246 may extend in an asymmetrical manner from the main portion 242 with respect to the sagittal plane of the patient’s head.

[0282] FIG. 52 is an example of a patient interface 5230 (or patient interface assembly), wherein the headgear 234 may include an overhead strap portion 268 and / or a chin strap portion 264. This enables the headgear to be fitted to the patient in a manner requiring access only to the front of the patient’s head, thus allowing the headgear to be fitted to the patient while they are lying supine. The headgear 234 may extend between a pair of nodes 261 , 263 respectively, at two opposite lateral portions of the headgear 234 (e.g., a first lateral portion and a second lateral portion of the headgear 234). The two opposite lateral portions of the headgear 234 may be portions of the headgear 234 respectively to the left and to the right of the nasal interface 232 as described previously. At least one electrical sensing arrangement in the form of a strip 249 having one or more electrical sensing elements 252 may be provided between nodes 261 , 263. In the example depicted, the electrical sensing arrangement includes a forehead strip 249a and a nose strip 249b. It is to be understood however that one of these strips may be omitted in some examples, or that a different electrical sensing arrangement may be incorporated as described elsewhere herein. In some configurations, the one or more strips 249 of the electrical sensing arrangement may be pivotably attached to the nodes 261 , 263 to allow for adjustment of the location ofthe one or more strips 249 on the patient’s face. In some embodiments the headgear 234 may be pivotably attached to the nodes 261 , 263. In some embodiments, straps of the headgear 234 including one or both of the overhead strap portion 268 and chin strap portion 264 may be adjustable e.g. to be tightened as previously described. In some embodiments, at least one of the strips 249 of the electrical sensing arrangement may be adjustable e.g. to be tightened, in a similar manner to the strap portions of the headgear 234. In some embodiments, the strip 249a, 249b may be configured to be adhered to the patient’s face for added stability. For example, the strip 249a, 249b may have an adhesive on the patient contacting side such that it can be adhered to the patient’s face whilst the electrical sensing elements 252 may or may not be configured to be adhered to the patient’s face.

[0283] FIG. 53 is an example of a patient interface 5330 (or patient interface assembly), wherein the headgear includes an overhead strap portion 268 having or more electrical sensing elements 252 is provided between nodes 261 , 263. The overhead strap portion 268 includes one or more adhesive patches 285 configured to anchor the overhead strap portion 268 to the patient’s forehead to retain the nasal interface 232 in place. One or more of the electrical sensing elements 252 of the overhead strap portion 268 may also include an adhesive surface or a frictional surface to facilitate attachment to the patient’s skin. In the example shown, the overhead strap portion 268 extends over the top portion of the patient’s head, such as at the top of the forehead. Accordingly, during positioning the overhead strap portion 268 may be positioned and oriented to cause the nasal interface 232 to bear against the nose of the patient from below. According to various embodiments, the overhead strap portion 268 may be of a predetermined length. The predetermined length may be based on the size and dimension of the head of the patient. For example, the predetermined length of the overhead strap portion 268 may be a length that may cause the overhead strap portion 268 to lay across the top of the patient’s forehead when worn for keeping the nasal interface 232 in place.

[0284] FIG. 54 is an example of a patient interface 5430 (or patient interface assembly), in which a strip 249 having or more electrical sensing elements 252 is provided between nodes 261 , 263 and the headgear comprises hook portions 267 configured to secure behind the patient’s ears. The hook portions 267 may be coupled with the nodes 261 , 263 respectively. While only one hook portion 267 is depicted in the side view of FIG. 54, it is to be appreciated that a second hook portion is provided to securethe patient interface 5430 over the patient’s opposing ear. In some embodiments, the hook portion 267 comprises a substantially rigid frame, such as a wire (which may be coated with e.g. plastic or silicon) or substantially rigid polymer frame shaped to hook over the top of the patient’s ear. In some embodiments, the hook portion may be adjustable by bending, to conform to the patient’s anatomy e.g. to accommodate different ear size and position on the patient’s head. Each hook portion 267 may be pivotably coupled with the respective nodes 261 , 263 although that need not be the case if the hook portion is adjustable. Accordingly, during positioning the hook portions 267 are applied over the patient’s ears and in some examples, adjusted, to cause the nasal interface to bear against the nose of the patient from the front. In the example shown, strip 249c having the one or more electrical sensing elements 252 extends over the patient’s nose. However it is to be understood that the strip 249 may be placed elsewhere on the patient’s face, such as over the patient’s forehead or over the top of the patient’s head, as depicted in other examples provided herein. It is also contemplated that the electrical sensing arrangement may consist of more than one strip 249 of electrical sensing elements. Hook portions 267 are intended to anchor the nasal interface 232 and the electrical sensing elements 252 in place during use. However in some examples one of more of the electrical sensing elements and / or the strip 249 may include adhesion surfaces and / or friction surfaces to further retain the patient interface 5430 in position during use.

[0285] FIG. 55 and FIG. 56 are examples of patient interfaces 5530 and 5630 (or patient assemblies) wherein the headgear 234 may include or consist of a strap portion 262 extending around the back of the patient’s head, retaining the nasal interface 232 in position during use. Two or more electrical sensing elements 252 are provided on one or more substantially rigid arms 269 which may be coupled with the headgear 234 or the patient interface 232. The arms 269 may include a wire (which may be coated with e.g. plastic or silicon) or substantially rigid polymer which, when the patient interface 5530, 5430 is applied to the patient, orients the one or more sensing elements towards desired sensing locations. In some embodiments, the arms 269 may be adjustable by bending, to manipulate the location of the one or more sensing elements e.g. to obtain a better signal when in use. Each arm 269 may be coupled with respective nodes 261 , 263. The coupling may be a pivotable coupling with the nodes 261 , 263. Alternatively or additionally, one or both arms 269 may include a pivot 269a which permits repositioning of the one or more sensing elements 252. Providinga pivot 269a may limit the range of adjustment permitted for relocation of the one or more sensing elements 252. In some examples, one or more of the electrical sensing elements 252 may include adhesion surfaces and / or friction surfaces to reduce movement (and signal artefact) and improve conduction between the body and electrode when in use. The adhesion surfaces may permit the electrical sensing elements 252 to be removably adhered to the patient and in some cases, re-adhered to permit repositioning to improve signal acquisition. In some examples, a plurality of electrical sensing elements 252 may be provided on a strip which is attached to the arm 269. A user may modify the strip by tearing off an end portion of the strip containing electrical sensing elements that are not required. The strip may be flexible to conform to the shape of the patient’s head. In some examples, the strip may be sufficiently flexible that the electrical sensing elements 252 are able to be applied to the patient in a non-straight line.

[0286] In the embodiment depicted in the side view of FIG. 55, an electrical sensing element 252 is provided on arm 269 which is coupled with node 263. It will be appreciated that a corresponding arm on the opposing side of the patient interface may also be coupled with node 261 . However, in the embodiment depicted in the side view of FIG. 56, two electrical sensing elements 252 are provided on arm 269 which is coupled with node 263. In this arrangement, it may not be necessary to provide a second arm on the opposing side of the patient interface 5630 since an adequate signal may be obtained using two or more electrical sensing elements 252 on a single arm 269. It is to be understood that multiple arms 269, each providing one or more than one electrical sensing element 252, and in any combination, may also be provided on either or both sides of the patient interface 5630.

[0287] FIG. 57 is an example of a patient interface 5730 (or patient assembly) wherein headgear may include a strap portion 262 extending around the back of the patient’s head, retaining the nasal interface 232 in position during use. Two or more electrical sensing elements 252 are provided to measure the patient’s response to audible signals introduced via in-ear speakers 290. While the example depicted shows in-ear speakers 290 in each ear, it is contemplated that a single in-ear speaker may provide sufficient auditory stimulation to determine DoA using the two or more electrical sensing elements 252. While the sensing elements 252 depicted are located proximal to the ear, it is to be appreciated that any of the headgear 234 and electrical sensing arrangements disclosed herein may be adopted to monitor the patient’s physiologicalresponse to the auditory stimulus provided via the one or more in-ear speakers 290. Over-ear speakers may be provided as an alternative. The auditory stimulus may comprise a range of one or more sounds such as tonal sounds, clicks, beeps, music, speech or the like. The in-ear speakers 290 may comprise a wired or wireless connection to the auditory stimulus source, utilising methods known in the art. In some examples, one or more in-ear speakers 290 form part of the patient interface 5730 and may be attached to the patient interface 234 or the nasal interface 232, such as the tubing thereof. Attachment of the in-ear speaker 290 to the patient interface 5730 may reduce the risk of the in-ear speakers being inadvertently left off the patient during use.

[0288] FIG. 39 shows an example of the nasal interface 232 with the two or more electrical sensing elements 252 incorporated therein according to various embodiments. According to various embodiments, the nasal interface 232 of FIG. 39 may be retained by the headgear 234 or may be standalone without being connected to any headgear 234. As shown, the nasal interface 232 may include two electrical sensing elements 252 disposed at the first lateral portion 244 of the nasal interface 252 and / or two electrical sensing elements disposed at the second lateral portion 246 of the nasal interface 232. According to various embodiments, the two electrical sensing elements 252 at the first lateral portion 244 may be arranged side-by-side lengthwise. Similarly, the two electrical sensing elements 252 at the second lateral portion 246 may be arranged side-by-side lengthwise. In other words, at the first lateral portion 244 of the nasal interface 232, a first of the two electrical sensing elements 252 may be proximal to the main portion 242 of the nasal interface 232 and a second of the two electrical sensing elements 252 may be distal from the main portion 242 of the nasal interface 232. Correspondingly, at the second lateral portion 246 of the nasal interface 232, a first of the two electrical sensing elements 252 may be proximal to the main portion 242 of the nasal interface 232 and a second of the two electrical sensing elements 252 may be distal from the main portion 242 of the nasal interface 232.

[0289] While not shown, it is understood that, according to various other embodiments, the two electrical sensing elements 252 at the first lateral portion 244 may be arranged side-by-side along a direction transverse to the length of the first lateral portion 244. Similarly, the two electrical sensing elements 252 at the second lateral portion 246 may be arranged side-by-side along a direction transverse to the length of the second lateral portion 246. Accordingly, at the first lateral portion 244, the two electrical sensing elements 252 may be arranged vertically along a width of the first lateralportion 244. Correspondingly, at the second lateral portion 246, the two electrical sensing elements 252 may be arranged vertically along a width of the second lateral portion 246. In other embodiments (not shown), the two electrical sensing elements 252 may be arranged diagonally with respect to the length of the first lateral portion 244. Correspondingly, at the second lateral portion 246, the two electrical sensing elements 252 may be arranged diagonally with respect to the length of the second lateral portion 246. In further embodiments still (not shown), the two electrical sensing elements 252 may be arranged in another geometric layout, or in an irregular layout, with respect to the first lateral portion 244 and / or the second lateral portion 246.

[0290] According to various embodiments, an attachment arrangement 4082 may be provided to the first lateral portion 244 and / or the second lateral portion 246. The attachment arrangement 4082 may include an adhesive surface and / or a frictional surface (e.g. on the patient facing side). According to various embodiments, the attachment arrangement 4082 may include, but is not limited to a pad, a patch, a disc, a liner, a sheet, or a film. The attachment arrangement 4082 may be attached or coupled to the first lateral portion 244 and / or the second lateral portion 246 so as to provide the adhesive surface or the frictional surface to the first lateral portion 244 and / or the second lateral portion 246. According to various embodiments, the attachment arrangement 4082 may be removably or permanently attached or coupled to the first lateral portion 244 and / or the second lateral portion 246. For example, the attachment arrangement 4082 may include a single sheet or panel or piece permanently attached or coupled to the first lateral portion 244 and / or the second lateral portion 246 with the adhesive surface and / or the frictional surface of the attachment arrangement 4082 on the patient facing side of the nasal interface 232. As another example, the attachment arrangement 4082 may include a releasable connection arrangement, such as a two-part releasable attachment or connection arrangement described later, so as to be removably attached or coupled to the first lateral portion 244 and / or the second lateral portion 246 with the adhesive surface and / or the frictional surface of the attachment arrangement 4082 on the patient facing side of the nasal interface 232.

[0291] According to various embodiments, when the nasal interface 232 with the attachment arrangement 4082 is worn, the attachment arrangement 4082 may adhere the nasal interface 232 to the face of the patient such that the nasal interface 232 may be retained or maintained in place on the face of the patient. Accordingly, to wear thenasal interface 232, the at least one nasal delivery element 348 may be inserted into the nare of the nose of the patient, the main portion 242 of the nasal interface 232 may be placed to bear against the nose of the patient, and the first lateral portion 244 and / or the second lateral portion 246 with the attachment arrangement 4082 may be pressed onto the patient’s cheek or buccal area such that the adhesive surface and / or the frictional surface of the attachment arrangement 4082 on the patient facing side of the nasal interface 232 may adhere the nasal interface 232 to the face of the patient.

[0292] FIG. 40A shows an example of the attachment arrangement 4082 being a dermal patch 4085. As shown, the dermal patch 4085 may have a user side 4085a that faces the patient’s skin and an interface side 4085b that faces the nasal interface 232. The adhesive surface and / or the frictional surface may be at the user side 4085a of the dermal patch 4085 for attaching to the skin of the patient. As an example, the user side of the dermal patch 4085 may be attached to the skin of the patient by a dermatologically sensitive adhesive, such as a hydrocolloid. Further, the interface side of the dermal patch 4085 may be affixed (e.g. permanently) to a patch receiving area 4087 of the first lateral portion 244 and / or the second lateral portion 246. Accordingly, the interface side 4085b of the dermal patch 4085 may be integrated with or suitably adhered to the nasal interface 232.

[0293] According to various embodiments, the attachment arrangement 4082 may be a releasable connection arrangement. Further, the releasable connection arrangement may include, but not limited to, a two-part releasable attachment or connection arrangement. FIG. 40B shows an example of the attachment arrangement 4082 being the two-part releasable attachment or connection arrangement according to various embodiments. According to various embodiments, the releasable connection arrangement may act between a pair of patches 4085, 4089 that are affixed to the patient and the nasal interface 232 respectively.

[0294] A first patch of the pair of patches may be a dermal patch 4085 for adhering to or otherwise attaching to the patient’s skin. The dermal patch 4085 may have a user side that faces the patient’s skin and an interface side that faces the nasal interface 232. The user side of the dermal patch 4085 may be attached to the skin of the patient by a dermatologically sensitive adhesive, such as a hydrocolloid. Hence, the user side of the dermal patch 4085 may be provided with a patient attachment part 4088a. The interface side of the dermal patch 4085 may be provided with a first part 4088b of the two-part releasable attachment or connection arrangement. Accordingly, the dermalpatch 4085 may be formed by the patient attachment part 4088a and the first part 4088b of the two-part releasable attachment or connection arrangement.

[0295] A second patch may be a nasal interface patch 4089. The nasal interface patch 4089 may also have a patient side and an interface side. The patient side of the nasal interface patch 4089 may be disposed adjacent the dermal patch 4085 when the two- part releasable attachment or connection arrangement is engaged. A complimentary second part 4089a of the two-part releasable attachment or connection arrangement may be affixed to the patient side of the nasal interface patch 4089, so that the respective parts 4088b, 4089a of the two-part releasable attachment or connection arrangement may be easily engageable when the patches 4085, 4089 are brought together. The interface side of the nasal interface patch 4089 may be affixed to the nasal interface 232. For example, the interface side of the nasal interface patch 4089 may be affixed (e.g. permanently) to a patch receiving area 4087 of the first lateral portion 244 and / or the second lateral portion 246 of the nasal interface 232. Accordingly, the nasal interface patch 4089 may be integrated with or suitably adhered to the nasal interface 232.

[0296] A part or corner of the nasal interface patch 4089 may include a region 4086 that does not attach to the dermal patch 4085. The general purpose of this is to allow a region (or tab) 4086 that can be more easily gripped by the user for removing or detaching the nasal interface patch 4089 and the dermal patch 4085 from each other. The region 4086 may be located towards an edge of the nasal interface patch 4089 and in some examples, such a region may be provided at opposing side edged of the patch for ease of access by a user on either side of the patch.

[0297] The two-part releasable attachment or connection arrangement may include a hook and loop material (such as Velcro™), a magnet or an array of magnets disposed on the respective patches 4085, 4089 with the poles suitably arranged, an adhesive arrangement that is activated when the patches 4085, 4089 are urged together or another suitable releasable coupling. When the releasable coupling includes a magnet or array of magnets, magnetic shielding may be utilised to minimise interference or signal artefact that may be caused by the coupling magnets. Alternatively or additionally such interference may be reduced or removed electronically by signal processing. The interface side of the dermal patch 4085 (i.e. the first part 4088b of the two-part releasable attachment or connection arrangement) may have one of a hook or a loop material, and the patient side of the nasal interface patch 4089 (i.e. thesecond part 4089a of the two-part releasable attachment or connection arrangement) may have the other of the hook or loop material, such that the dermal patch 4085 and the nasal interface patch 4089 may be releasably attachable or connectable to each other.

[0298] Reference to a hook and loop material generally mean any one of a wide variety of area type mechanical fasteners. For example, the Velcro™ product range includes hook and loop product where the hook component includes upstanding nylon hooks (formed as cut loops through a woven backing web) which engage with any complimentary loop pile material. The Velcro™ product range also includes extruded hook products, typically of a smaller size and which mate with “fluffy” non-woven fiber backing materials. These hook materials are designed to work with a range of loop substrates and in some cases, these hook materials act as loop substrates as well. Other similar systems include the Dual-Lock™ recloseable fastener system from 3M of St Paul, Minnesota USA. The common feature of these releasable fastening systems is that they engage at any part of the contact between the two parts of the two-part releasable attachment or connection arrangement. Precise alignment of individual connectors is not required because multitude of connectors are distributed across the area of the product. A wide range of releasable fastener systems within this field may be used in the releasable attachment system for providing releasable attachment between the dermal patch 4085 and the nasal interface patch 4089.

[0299] The first part 4088b of the two-part releasable attachment or connection arrangement may be adhered to the patient attachment part 4088a with a suitable adhesive and occupy up to 100% or less than about 90%, or about 85%, or about 75%, or about 60%, or about 50%, or about 40%, or about 30%, or about 20%, or about 10% of the interface side surface area of the patient attachment part 4088a so as to form the nasal interface side of the dermal patch 4085.

[0300] According to various embodiments, the dermal patch 4085 may be a generally planar pad having a thickness much less than both its width and its length. In some embodiments, the pad may have an overall oval or obround shape, but may take other shapes.

[0301] The pad may include the first part 4088b of the two-part releasable attachment or connection arrangement. In some embodiments, the construction of the dermal patch 4085 may be such that the first part 4088b of the two-part releasable attachment or connection arrangement may include a substrate and multitude of fastenerelements (with effective hooks, effective loops or other elements) provided across the area of the substrate. The substrate may be secured to the body of the dermal patch 4085. In some embodiments, the substrate may be secured by adhesive or by direct bonding during forming of the dermal patch 4085.

[0302] In some embodiments, the substrate may be smaller in area than the dermal patch 4085 and may be located on the dermal patch 4085 so that it does not reach any edge of the dermal patch 4085. In this way, the edge of the substrate may spread from the edge of the dermal patch 4085 all around the perimeter of the substrate.

[0303] In some embodiments, the substrate for the first part 4088b of the two-part releasable attachment or connection arrangement may be flexible such that the plane of the substrate may bend to follow a surface that is curved in one direction. However, the substrate is typically not also stretchable to be able to follow a surface curved in two orthogonal directions. However, the pad of the dermal patch 4085 may be stretchable and conformable to surfaces curved in more than one direction such as may be required to conform to the contours of the location of placement on the patient.

[0304] According to some embodiments, this difficulty may be alleviated by providing the first part 4088b of the two-part releasable attachment or connection arrangement in a form wherein the portion of substrate may be divided by at least one slit or at least one slot into regions that different parts of the substrate portion may bend independently and thus the overall form of the substrate portion may deform to substantially match a surface curved in two directions. This may be achieved even though the substrate portion is only curved in one direction at any individual location on the substrate portion.

[0305] Referring to FIG. 40A and FIG. 40B, according to the embodiments as shown, the dermal patch 4085 of FIG. 40A or the pair of patches 4085, 4089 of FIG. 40B may have holes such that the electrical sensing elements 252 disposed at the first lateral portion 244 and / or the second lateral portion 246 may be exposed through the holes. Accordingly, the dermal patch 4085 of FIG. 40A or the pair of patches 4085, 4089 of FIG. 40B may not cover or conceal the electrical sensing elements 252 when attaching or coupling the dermal patch 4085 of FIG. 40A or the pair of patches 4085, 4089 of FIG. 40B to the first lateral portion 244 and / or the second lateral portion 246. According to some other embodiments, the dermal patch 4085 of FIG. 40A and / or FIG. 40B may have the electrical sensing elements 252 affixed to the patient facing side thereof. Accordingly, the electrical sensing elements 252 may be at the dermal patch 4085such that the electrical sensing elements 252 and the dermal patch 4085, together, may be attached or coupled to the first lateral portion 244 and / or the second lateral portion 246.

[0306] FIG. 41 shows the electrical sensing elements 252 for the first lateral portion 244 and / or the second lateral portion 246 according to various embodiments. FIG. 42 shows a mesh 4284 separated from the electrical sensing element 252 according to various embodiments. FIG. 43 shows the mesh 4284 and an insulating backing 4286 separated from the electrical sensing element 252 according to various embodiments. As shown, as an example, the electrical sensing element 252 may be in the form of a disc electrode and have a spikey surface serving as the frictional surface of the electrical sensing element 252. The spikey surface may increase contact pressure with the skin to prevent movement of the electrical sensing element 252 relative to the skin. Further, the insulating backing 4286 may provide insulation to avoid interference with neighbouring electrical sensing element 252. In addition, the mesh 4284 may contain electro-conductive gel to lower the impedance between the electrical sensing element 252 and the skin further improving the conductance of signals obtained by the electrical sensing arrangement 250.

[0307] FIG. 44 to FIG. 47 show an example of the nasal interface 232 for the patient interface 230, 1230, 1330, 1430, 1530, 1630, 1730, 1830, 1930, 2030, 2330, 2530, 2830, 2930, 3030, 3130, 3230, 3530, 3630, 3730, 3830, 5230, 5330, 5430, 5530, 5630, 5730 according to various embodiments. FIG. 48 shows another example of the nasal interface 232 for the patient interface 230, 1230, 1330, 1430, 1530, 1630, 1730, 1830, 1930, 2030, 2330, 2530, 2830, 2930, 3030, 3130, 3230, 3530, 3630, 3730, 3830, 5230, 5330, 5430, 5530, 5630, 5730 according to various embodiments.

[0308] According to various embodiments, the nasal interface 232 may include at least one gases flow port 4445 disposed at either one of (i) the main portion 242 of the nasal interface 232 or (ii) the first lateral portion 244 and / or the second lateral portion 246 of the nasal interface 232. The at least one gases flow port may be for receiving a gases flow. The at least one gases flow port 4445 may be in fluid communication with the at least one nasal delivery element 348. Accordingly, a supply of gases flow may be provided to the at least one gases flow port 4445 of the nasal interface 232 for supplying gases flow therethrough to the at least one nasal delivery element 348 such that the at least one nasal delivery element 348 may deliver gases flow into the nares of the nose of the patient. Accordingly, the at least one gases flow port may serve asa flow inlet for the nasal interface 232 and the at least one nasal delivery element 348 may serve as a flow outlet for the nasal interface 232.

[0309] FIG. 44 to FIG. 47 exemplify a nasal interface 232 including a nasal cannula and including a gases delivery side member 4443 (serving as the second lateral portion 246 as shown, but it is understood that it can also serve as the first lateral portion 244 in other example embodiments) configured to deliver apparatus gases (for example gas flow from a flow source) to the patient via a manifold 4441 (serving as the main portion 242) to a delivery outlet including a pair of nasal prongs (serving as the nasal delivery elements 348). The pair of nasal prongs may extend from the manifold 4441 . The gases delivery side member 4443 may extend from a first side of the manifold 4441 and the nasal interface 232 may further include a non-delivery side member 4447 (serving as the first lateral portion 244 as shown, but it is understood that it can also serve as the second lateral portion 246 in other example embodiments) extending from a second side of the manifold 4441 which is opposite to the first side. The non-delivery side member 4447 may include an end 4447a configured for connection to the head gear 234 (e.g. the head strap portion 262).

[0310] The gases delivery side member 4443 may include a collapsible portion 4443b configured to move from the normally open configuration shown in FIG. 44, FIG. 46 and FIG. 47 to a collapsed configuration in which apparatus gas flow through the collapsible portion 4443b may be reduced or stopped. The collapsible portion 4443b may be configured to move to the collapsed configuration upon application of a collapsing force such as from a patient mask placed over the patient’s face and wherein a seal of the mask is pressed down upon the collapsible portion 4443b. The gases delivery side member 4443 may also include a non-collapsible portion 4443c configured to remain open during application of the collapsing force onto the collapsible portion 4443b. The non-collapsible portion 4443c may be collapsible but would be less collapsible than the collapsible portion 4443b. For example, for a given force, the collapsible portion 4443b may collapse to a greater extent (e.g. greater reduction in the cross-sectional flow path area) than non-collapsible portion 4443c and / or that a force greater than the minimum amount of force required to collapse the collapsible portion 4443b would be required to collapse the non-collapsible portion 4443c.

[0311] One end of the non-collapsible portion 4443b may include a delivery inlet 4443a (serving as the at least one gases flow port 4445) for receiving apparatus gas flow.The nasal interface 232 may further include a gas path connector 4449 which has a rigid structure and includes a delivery inlet 4449a and a delivery outlet 4449b. The gas path connector delivery inlet 4449a may be connectable to an apparatus gas supply via a conduit (similar to conduit 1 12 in FIG. 48). The gas path connector delivery outlet 4449b may be connected to the delivery inlet 4443a of the non-collapsible portion 4443b. The gas path connector 4449 may also be connected to the head gear 234 (e.g. the head strap portion 262) at an opposite end of the head gear 234 to that which may be connected to the headstrap end 4447a of the non-delivery side member 4447.

[0312] FIG. 45 illustrates a cross-section of the non-collapsible portion 4443c which may include wall 4443d of uniform thickness. FIG. 46 and FIG. 47 illustrate a crosssection of the collapsible portion 4443b which may include a wall 4443e of non-uniform thickness. The collapsible portion 4443b may have an elongate cross-section and, in particular, a stadium-shaped cross section which may include a pair of longitudinal sides 4443f extending between a pair of ends 4443g. As shown in FIG. 47, a thinwalled portion 4443h may be provided at each of the ends 4443g. The thin wall portions 4443h may be configured to provide fold lines at which the collapsible portion 4443b may bend or fold upon application of the collapsing force.

[0313] According to various embodiments, the at least one gases flow port 4445 (i.e. the delivery inlet 4443a) may be disposed at the gases delivery side member 4443 (serving as the second lateral portion 246 as shown, but it is understood that it can also serve as the first lateral portion 244 in other example embodiments). In such an embodiment, the main portion 242 of the nasal interface 232 (i.e. the manifold 4441 ) and the at least one nasal delivery element 348 (i.e. the nasal prongs) may be in fluid communication. Further, the gases delivery side member 4443 may be capable of allowing gases flow therethrough. On the other hand, the non-delivery side member 4447(serving as the first lateral portion 244 as shown, but it is understood that it can also serve as the second lateral portion 246 in other example embodiments) may not be capable of delivering gases flow. While it is illustrated that the second lateral portion 246 includes the gases delivery side member 4443 and the first lateral portion 244 includes the non-delivery side member 4447, it is understood that, according to various embodiments, the reverse may be possible, whereby the first lateral portion 244 may include the gases delivery side member 4443 and the second lateral portion 246 may include the non-delivery side member 4447.

[0314] According to various embodiments, the at least one gases flow port 4445 (i.e. the delivery inlet 4443a) may be at an end of the gases delivery side member 4443 distal from the manifold 4441 . Accordingly, the delivery inlet 4443a may be capable of receiving the gases flow and the gases delivery side member 4443 may supply the gases flow to the manifold 4441 , which in turn supply the gases flow to the at least one nasal delivery element 348 for delivering the gases flow into the nares of the nose of the patient.

[0315] According to various embodiments, the headgear 234 may be connected to a tab 4449c at a distal end of the second lateral portion 246 and a tab 4447b at a distal end of the first lateral portion 244. Accordingly, the headgear 234 may retain the nasal interface 232 by holding the tab 4449c of the second lateral portion 246 and the tab 4447b of the first lateral portion 244.

[0316] Another example of the nasal interface 232 is shown in FIG. 48 to FIG. 50. The nasal interface 232 may include a face mount part 4580, a pair of nasal prongs (serving as the nasal delivery elements 348), a gases flow manifold part 4588 and a gas conduit 1 12. The face mount part 4580 may include an upper (first) portion 4580a (serving as the main portion 242) from which the nasal prongs (i.e. nasal delivery elements 348) extend and a face contacting (second) portion 4580b that is configured to contact the patient’s upper lip when in use. The upper portion 4580a and the face contacting portion 4580b may be at an angle to one another and may optionally be substantially perpendicular to one another. The face mount part 4580 and the pair of nasal prongs (i.e. nasal delivery elements 348) may preferably be integrally moulded as one piece from a soft plastics material such as silicone or thermoplastic elastomer, although in other forms the face mount part 4580 and the prongs (i.e. nasal delivery elements 348) may be separate, but capable of attachment together for use. In some configurations, the face mount part 4580 and the nasal prongs (i.e. nasal delivery elements 348) may be formed from the same or different material. The nasal prongs (i.e. nasal delivery elements 348) may be tubular in shape and may be consistent in diameter but may be shaped to fit the contours of the human nares. The prongs (i.e. nasal delivery elements 348) may be angled towards a central plane bisecting the face mount part 4580 between the prongs. The prongs (i.e. nasal delivery elements 348) may be curved to point the outlets of the prongs toward the back of the patient’s head when in use. The prongs (i.e. nasal delivery elements 348) may include an internal and / or external cross-sectional shape transverse to a direction of flow through each prong when inuse, that may be elliptical, for example a circle or substantially elliptical, for example an oval. The shape and / or dimensions of each prong (i.e. nasal delivery elements 348) may be consistent or may change along its length. The prongs (i.e. nasal delivery elements 348) may be configured to be non-sealing with the patient’s nares in use such that there is a gap between the prongs and the patient’s nares. This may allow continuous flow of gas between the prongs (i.e. nasal delivery elements 348) and the patient’s nares when in use.

[0317] The face mount part 4580 may include side arms 4581 , 4583 (serving as the first lateral portion 244 and the second lateral portion 246) extending laterally from the sides of the face mount part 4580. Together with the headgear 234, the side arms 4581 , 4583 may help to hold the nasal interface 232 in place on the patient’s face. The ends of each side arm 4581 , 4583 may include one or more slots to allow an end of a strap of the headgear 234 to thread through. This may provide for an adjustable coupling between the headgear 234 and the side arm 4581 , 4583. Other attachment mechanisms other than slots are also envisaged, such as buckles and clips.

[0318] The face mount part 4580 may further include an auxiliary portion 4580c (or a third portion) extending from the upper portion 4580a and connects to the face contacting portion 4580b to form a recess 4586 that may be capable of receiving the gases flow manifold part 4588. In the embodiment shown, the recess 4586 may provide for a horizontal side entry of the gases flow manifold 4588. The gases flow manifold 4588 may therefore be laterally inserted into the recess 4586 via one lateral side of the face mount part 4580, in a direction that is transverse to the length of the prongs (i.e. nasal delivery elements 348). As the recess 4586 may include two lateral openings, the gases manifold part 4588 may be inserted into the recess 4586 via a left or a right side of the face mount part 4580. This may allow the nasal interface 232 to be configured to allow gases flow to the patient from either the left or right side of the nasal interface 232. The gases flow manifold 4588 may be attached to or integrally formed with the gas conduit 1 12. The nasal prongs (i.e. nasal delivery elements 348) may include flow passages that extend through the face mount part 4580 and into the recess 4586. The assembly of the face mount part 4580 and the gases flow manifold part 4588 may form a manifold. The gases flow manifold part 4588 may be blocked at one end 4588b but may be attached to the gas conduit 1 12 at the other end. The gases flow manifold 4588 has an opening 4588a that may act as an exit for gases received from the gas conduit 1 12. The opening 4588a is shown as an elongateopening but other shapes are also envisaged. The gases flow manifold 4588 may be more rigid or may include a material that is more rigid than the face mount part 4580. Due to the relative rigidities / flexibilities of the gases manifold part 4588 and the face mount part 4580, the gases flow manifold part 4588 may be pushed through the recess 4586 in the face mount part 4580 and the opening 4588a in the gases flow manifold part 4588 may meet with the flow passages of the prongs (i.e. the nasal delivery element 348). Therefore, in use, gases flowing through the gas conduit 1 12 and into the gases flow manifold part 4588 exit through the opening 4588a and into the tubular passageways in the prongs (i.e. the nasal delivery element 348), then into the patient's nares.

[0319] In order to assist with maintaining the gases flow manifold part 4588 within the recess 4586, the gases flow manifold part 4588 may be provided with a recessed portion 4588c and lip areas 4588d, 4588e. When engaged with the face mount part 4580, the auxiliary portion 4580c forming part of the recess 4586 sits within the recessed portion 4588c and the edges of the auxiliary portion 4588 abut the lips 4588d, 4588e formed on the gases flow manifold part 4588. Additionally, or alternatively, the gases flow manifold part 4588 may include one or more flanges 4588f that may be configured to engage with a part of the upper portion 4580a to retain the gases flow manifold 4588 with the face mount part 4580. The one or more flanges 4588f may be located about a periphery of the opening 4588c. In some configurations, the one or more flanges 4588f may be a single flange that extends about the entirety of the periphery of opening 4588f.

[0320] According to various embodiments, the at least one gases flow port may be disposed at the upper portion 4580a (i.e. the main portion 242) of the face mount part 4580 of the nasal interface 232. Accordingly, the at least one gases flow port may be apertures in the upper portion 4580a (i.e. the main portion 242) providing fluid access to the prongs (i.e. the nasal delivery elements 348). For example, the apertures of the upper portion 4580a (i.e. the main portion 242) may open into the flow passage of the prongs (i.e. the nasal delivery elements 348) so as to provide direct fluid access into the flow passage of the prongs (i.e. the nasal delivery elements 348). The prongs (i.e. the nasal delivery elements 348) may be extending from a top surface of the upper portion 4580a of the face mount part 4580 and the aperture may open into the flow passage of the prongs (i.e. the nasal delivery elements 348) from a bottom surface of the upper portion 4580a of the face mount part 4580.

[0321] According to various embodiments, the flow passages of the prongs (i.e. the nasal delivery elements 348) may be accessible via the aperture in the upper portion 4580a of the face mount part 4580 from within the recess 4586. When the gases flow manifold part 4586 is inserted into the recess 4586, the gases flow manifold part 4588 may become fluidly connected to the prongs (i.e. the nasal delivery elements 348) via the apertures of the upper portion 4580a from the recess 4586. For example, when inserted, the opening 4588a of the gases flow manifold part 4588 may be aligned to the apertures of the upper portion 4580a of the face mount part 4580. With the opening 4588a of the gases flow manifold part 4588 aligned to the aperture of the upper portion 4580a of the face mount part 4580, gases may flow from the conduit 1 12 into the gases flow manifold part 4588, and from the gases flow manifold part 4588 via the opening 4588a thereof and through the apertures of the upper portion 4580a into the flow passages of the prongs (i.e. the nasal delivery elements 348) for delivering into the nares of the nose of the patient.

[0322] According to various embodiments, the nasal interface 232 has a first lateral portion and a second lateral portion, either or both of which may be in fluid communication with a conduit 1 12 providing a flow of gases to the nasal interface 232 for delivery to the patient by the at least one nasal delivery element 348. The conduit 1 12 may be releasably couplable or permanently attached to or integrated with the nasal interface 232. A connection element for coupling the conduit 1 12 and nasal interface 232 may be conveniently located at a region of the nasal interface 232 that seeks to minimise interference with the user’s access to the patient. For example, a connection element may be positioned at a bend in the nasal interface 232 that seeks to align with the contours of the patient’s face e.g. to orient the conduit in a direction toward the patient’s ear, neck or shoulder when in use. In another example, the connection element may be a gas path connector 4449 positioned at the first lateral portion or the second lateral portion. The gas path connector 4449 receives the conduit in a horizontal direction. In a further example, the connection element may be a recess 4586 situated under the gases delivery element 348 to receive a part of the conduit 1 12 in a horizontal direction. In some embodiments the conduit 1 12 includes flexible tubing that is movable to optimise the user’s visual and clinical access to the patient’s face e.g. to monitor their appearance and / or conduct a medical procedure.

[0323] According to various embodiments, in addition to the at least one gases flow port 4445 or coupling with conduit 1 12, the nasal interface 232 may include electricalconnection points for the two or more electrical sensing elements 252 of the electrical sensing arrangement 250. Accordingly, the two or more electrical sensing elements 252 may be connected to an external electrical network via the electrical connection points at the nasal interface 232. The external electrical network may be connected to a signal processing device such that signals from the two or more electrical sensing elements 252 may be communicated to the signal processing device. Further, electrical wirings of the two or more electrical sensing elements 252 of the electrical sensing arrangement 250 may be routed to the nasal interface 232 so as to electrically connect the two or more electrical sensing elements 252 to the electrical connection points at the nasal interface 232.

[0324] According to various embodiments, the electrical connection points may be separate from the at least one gases flow port 4445 such that the electrical points and the at least one gases flow port 4445 may be disposed at different locations on the nasal interface. Accordingly, the conduit 1 12 and the external signal processing device may be separately and independently connected to the at least one gases flow port 4445 and the electrical connection points respectively.

[0325] According to various embodiments, the at least one gases flow port 4445 and the electrical connection points may be integrated together as a single connector on the nasal interface 232. Accordingly, the single connector may be configured for connecting to the conduit 1 12, which may be part of a gases flow delivery line, and the electrical network for communicating signals from the two or more electrical sensing elements 252.

[0326] FIG. 51 shows an end of the conduit 1 12 with an integrated connector 1 12a. The integrated connector 1 12a may include a gases flow passage 1 12b and one or more lumens 1 12c for electrical wires and connections. With the electrical wiring and connections integrated with the gases flow passage 1 12b into the conduit 1 12, there may be an improved component management and / or reduction in risk of damage to the wiring. The reduction in the number of wirings and conduits may also reduce tripping hazards in environments, such as wards, emergency departments and intensive care units (ICUs).

[0327] According to various embodiments, in addition to the electrical sensing arrangement 250, there may be provided at least one non-electrical sensing element. The at least one non-electrical sensing element may include one of a photosensing element, an optical sensing element, or a thermosensing element. The non-electricalsensing element may be physiological monitoring of the patient (or the subject). For example, the at least one non-electrical sensing element may be a pulse oximeter or a thermometer. Further, the at least one non-electrical sensing element may be attached to either one or both of the headgear 234 and the nasal interface 232.

[0328] Various embodiments have provided a patient interface that is capable of providing reliable nasal high flow whilst reliably monitoring electrical activity from the bodily parts of the patient (e.g., head or muscle) so as to determine the depth of anaesthesia (DoA) (or depth of sedation or level of consciousness). Various embodiments may minimally obstruct access to regions of the face of the patient. Various embodiments may also minimize the number of steps to take for wearing and positioning the patient interface. In various embodiments, a high flow nasal interface and an electrical sensing arrangement may be integrated in the patient interface, and the placement and / or disposition of the high flow nasal interface and the electrical sensing arrangement may have synergistic effects on their respective functions.

[0329] Conventionally, standalone high flow nasal interfaces can be unstable on a patient’s face due to the lack of or little interaction between the nasal delivery elements and the patient’s face, and pressures generated by the high flows, for example, prongs may easily fall out of the patient’s nares in an anterior direction when the patient is moved during a medical procedure. Overly securing the nasal interface may be undesirable as this can affect removal of the nasal interface during a medical procedure if required and / or structures (e.g., complex headgear) that aim to achieve this could reduce or prevent access to regions of the patient’s face for purposes of the medical procedure. Therefore, various embodiments have provided a patient interface having a nasal interface that may not only address the above issue, but has also integrated depth of anaesthesia (DoA) (or depth of sedation or level of consciousness) sensing and monitoring.

[0330] Various embodiments have also created minimal clutter (or reduced clutter) around the patient’s face which may interfere with the medical procedure as compared to conventional systems whereby high flow nasal interface and physiological sensing and monitoring are separate systems.

[0331] Various features and embodiments of the present disclosure are further set out in the Representative Features that follow.

[0332] While the invention has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that variouschanges, modification, variation in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.Representative FeaturesA1 . A patient interface assembly for a patient’s head, comprising: a headgear; a nasal interface comprising a main portion between a first lateral portion and a second lateral portion, and at least one nasal delivery element extending from the main portion, wherein the nasal interface is retained by the headgear with the first lateral portion and the second lateral portion held by the headgear; and an electrical sensing arrangement for detecting electrical activity of the patient to monitor a depth of anaesthesia of the patient, the electrical sensing arrangement comprising two or more electrical sensing elements distributed to one or both of the headgear and the nasal interface.A2. The patient interface assembly as in clause A1 , wherein each of the two or more electrical sensing elements is an electrode.A3. The patient interface assembly as in clause A2, wherein the electrode is an electroencephalography electrode.A4. The patient interface assembly as in any one of clauses A1 to A3, wherein each of the two or more electrical sensing elements is in the form of a cup, a disc, a patch, a pad or at least one needle.A5. The patient interface assembly as in any one of clauses A1 to A4, wherein at least one of the two or more electrical sensing elements comprises an adhesive surface and / or a frictional surface.A6. The patient assembly as in clause A5, wherein the adhesive surface and / or frictional surface comprises part of one or both of the headgear and the nasal interface.A7. The patient interface assembly as in any one of clauses A1 to A6, wherein the electrical sensing arrangement comprises three or more electrical sensing elements.A8. The patient interface assembly as in any one of clauses A1 to A7, wherein at least one of the two or more electrical sensing elements is fixedly attached to one or both of the headgear and the nasal interface.A9. The patient interface assembly as in clause A8, wherein the at least one of the two or more electrical sensing elements is embedded in one or both of the headgear and the nasal interface.A10. The patient interface assembly as in any one of clauses A1 to A7, wherein at least one of the two or more electrical sensing elements is movably attached to one or both of the headgear and the nasal interface in a manner so as to be translatable between different positions thereof.A11 . The patient interface assembly as in clause A10, wherein, when the at least one of the two or more electrical sensing elements is movably attached to the headgear, the at least one of the two or more electrical sensing elements is attached to a slide attachment, the slide attachment comprising a slide channel through which a strap of the headgear is fitted such that the slide attachment is slidable relative to the strap of the headgear for moving said electrical sensing element along the strap of the headgear.A12. The patient interface assembly as in any one of clauses A1 to A7, A10 or A11 , wherein at least one of the two or more electrical sensing elements is removably attached to one or both of the headgear and the nasal interface.A13. The patient interface assembly as in any one of clauses A1 to A12, wherein the headgear comprises a network of straps, wherein the network of straps comprises a pair of nodes respectively at two opposite lateral portions of the headgear corresponding to left and right portions of the headgear with the nasal interface being at an anterior position of the headgear.A14. The patient interface assembly as in clause A13, wherein the network of straps comprises a first strap segment extending from a first node of the pair of nodes to the first lateral portion of the nasal interface and a second strap segment extending from a second node of the pair of nodes to the second lateral portion of the nasal interface.A15. The patient interface assembly as in any one of clauses A1 to A14, further comprising at least one non-electrical sensing element attached to one or both of the headgear and the nasal interface, wherein the at least one non-electrical sensing element comprises one of a photosensing element, an optical sensing element, or a thermosensing element.A16. The patient interface assembly as in any one of clauses A1 to A15, wherein the at least one nasal delivery element is a nasal prong.A17. The patient interface assembly as in clause A16, wherein the nasal interface comprises two nasal prongs.A18. The patient interface assembly as in clause A17, wherein the two nasal prongs are of different dimensions.A19. The patient interface assembly as in clause A17, wherein the two nasal prongs are of a same dimension.A20. The patient interface assembly as in any one of clauses A1 to A19, wherein the headgear is conformable to the patient’s head for wearing on the patient’s head, wherein, when the headgear is worn on the patient’s head, the nasal interface is retained to bear against a nose of the patient along a first vector to maintain the nasal interface in a position and an orientation for delivering consistent gases flow into the nose of the patient, and at least one of the two or more electrical sensing elements of the electrical sensing arrangement is retained to bear against a corresponding position of the patient’s head along a second vector to maximise contact with the corresponding position of the patient’s head.A21 . The patient interface assembly as in clause A20 wherein the first vector forms an angle with a transverse plane of the patient’s head and is directed towards a coronal plane of the patient’s head, wherein the angle is between 0° and 90°.A22. The patient interface assembly as in clause A20 or A21 , wherein the second vector is directed substantially perpendicular towards the corresponding position of the patient’s head.A23. The patient interface assembly as in any one of clauses A20 to A22, wherein the headgear is resilient and is capable of returning to a contracted state for conforming the headgear to the patient’s head after being widened to an expanded state.A24. The patient interface assembly as in any one of clauses A20 to A23, wherein the headgear comprises elastic material stretchable to conform the headgear to the patient’s head.A25. The patient interface assembly as in any one of clauses A20 to A24, wherein the headgear comprises an adjustable arrangement to tighten the headgear for conforming to the patient’s head.A26. The patient interface assembly as in clause A25, wherein the adjustable arrangement comprises one or more or a combination of a ring, a slide, a hook, a buckle, or a strap adjuster for adjusting one or more straps of the headgear.A27. The patient interface assembly as in any one of clauses A1 to A26, wherein the headgear comprises a head strap portion that forms a continuous loop with the nasal interface.A28. The patient interface assembly as in clause A27, wherein the head strap portion extends from the first lateral portion of the nasal interface to the second lateral portion of the nasal interface.A29. The patient interface assembly as in clause A27 or A28, wherein the two or more electrical sensing elements of the electrical sensing arrangement are distributed along the continuous loop.A30. The patient interface assembly as in any one of clauses A27 to A29, wherein a distribution of the two or more electrical sensing elements from the first lateral portion of the nasal interface to a mid-point of the head strap portion is symmetrical with a distribution of the two or more electrical sensing elements from the second lateral portion of the nasal interface to the mid-point of the head strap portion.A31 . The patient interface assembly as in any one of clauses A27 to A30, wherein each of the two or more electrical sensing elements is disposed along the continuous loop at a corresponding predetermined distance from a mid-point of the main portion of the nasal interface.A32. The patient interface assembly as in any one of clauses A27 to A31 , wherein the continuous loop formed by the head strap portion of the headgear and the nasal interface is configured to loop across a top region of the patient’s head.A33. The patient interface assembly as in any one of clauses A1 to A32, wherein the headgear comprises a nasal strap portion for wearing over a nose bridge of the patient.A34. The patient interface assembly as in clause A33, wherein the nasal strap portion extends from the first lateral portion of the nasal interface to the second lateral portion of the nasal interface.A35. The patient interface assembly as in clause A33 or A34, wherein the nasal strap portion is of a predetermined length so as to maintain the nasal interface in place when worn.A36. The patient interface assembly as in any one of clauses A33 to A35, wherein the nasal strap portion is configured to apply a countering force to resist a load on one or more sides of the nasal interface.A37. The patient interface assembly as in any one of clauses A33 to A35, wherein at least one of the two or more electrical sensing elements of the electrical sensing arrangement is disposed at the nasal strap portion of the headgear.A38. The patient interface assembly as in clause A37, wherein a disposition of the at least one of the two or more electrical sensing elements and the nasal strap portion is configured to apply a countering force to resist a load on one or more sides of the nasal interface.A39. The patient interface assembly as in any one of clauses A1 to A38, wherein the headgear comprises a forehead strap portion for wearing across a forehead of the patient.A40. The patient interface assembly as in clause A39, wherein at least one of the two or more electrical sensing elements of the electrical sensing arrangement is disposed at the forehead strap portion of the headgear.A41 . The patient interface assembly as in any one of clauses A1 to A40, comprising at least one electrical sensing element disposed at the first lateral portion of the nasal interface and at least one further electrical sensing element disposed at the second lateral portion of the nasal interface.A42. The patient interface assembly as in any one of clauses A1 to A40, comprising two electrical sensing elements disposed side-by-side lengthwise at the first lateral portion of the nasal interface and / or two electrical sensing elements disposed side-by-side lengthwise at the second lateral portion of the nasal interface.A43. The patient interface assembly as in any one of clauses A1 to A40, comprising two electrical sensing elements disposed at the first lateral portion of the nasal interface and side-by-side along a direction transverse to a length of the first lateral portion, and / or two electrical sensing elements disposed in at the second lateral portion of the nasal interface and side-by-side along a direction transverse to a length of the second lateral portion.A44. The patient interface assembly as in any one of clauses A1 to A43, wherein the nasal interface comprises at least one gases flow port disposed at one of (i) the main portion or (ii) the first lateral portion and / or the second lateral portion of the nasal interface, the at least one gases flow port being for receiving a gases flow, wherein the at least one gases flow port is in fluid communication with the at least one nasal delivery element.A45. The patient interface assembly as in clause A44, wherein, when the at least one gases flow port is disposed at the first lateral portion, the main portion comprises a manifold, the first lateral portion comprises a gases delivery side member extending from a corresponding side of the manifold, and the second lateral portion comprises a non-delivery side member extending from a corresponding opposite side of the manifold, wherein an end of the gases delivery side member distal from the manifold comprises a delivery inlet serving as the at least one gases flow port, wherein the at least one nasal delivery element extends from the manifold.A46. The patient interface assembly as in clause A44, wherein when the at least one gases flow port is disposed at the second lateral portion, the main portion comprises a manifold, the second lateral portion comprises a gases delivery side member extending from a corresponding side of the manifold, and the first lateral portion comprises a non-delivery side member extending from a corresponding opposite side of the manifold, wherein an end of the gases delivery side member distal from the manifold comprises a delivery inlet serving as the at least one gases flow port, wherein the at least one nasal delivery element extends from the manifold.A47. The patient interface assembly as in clause A45 or A46, wherein the gases delivery side member comprises a collapsible portion operable to change between a normally open configuration and a collapsed configuration.A48. The patient interface assembly as in clause A47, wherein the collapsible portion changes from the normally open configuration to the collapsed configuration upon application of a collapsing force to the collapsible portion.A49. The patient interface assembly as in any one of clauses A45 to A48, further comprising a gas path connector connected to the delivery inlet.A50. The patient interface assembly as in clause A44, wherein, when the at least one gases flow port is disposed at the main portion, the at least one gases flow port is an opening in the main portion providing direct fluid access into a flow passage of the at least one nasal delivery element.A51 . The patient interface assembly as in clause A50, wherein the nasal interface comprises a face mount part with an upper portion serving as the main portion from which the at least one nasal delivery element extends, and the at least one gases flow port is an aperture in the upper portion opening into the flow passage of the at least one nasal delivery element extending from the upper portion of the face mount part.A52. The patient interface assembly as in clause A51 , wherein the face mount part comprises a face contacting portion, wherein upper portion and the face contacting portion are at an angle to one another.A53. The patient interface assembly as in clause A52, wherein the face mount part comprises an auxiliary portion extending from the upper portion to the face contacting portion to form a recess capable of receiving a gases flow manifold part.A54. The patient interface assembly as in clause A53, wherein the aperture in the upper portion is located along a segment of the upper portion forming the recess with the face contacting portion and the auxiliary portion.A55. The patient interface assembly as in clause A53 or A54, wherein the recess comprises two lateral openings for lateral insertion of the gases flow manifold part into the face mount part.A56. The patient interface assembly as in clause A55, wherein the gases flow manifold part is at an end of a gas conduit, wherein an end of the gases flow manifold part distal from the gas conduit is closed and the gases flow manifold parthas an opening along a side of the gases flow manifold part, whereby the opening of the gases flow manifold part is capable of being aligned to the aperture of the upper portion of the face mount part when inserted into the face mount part via any one of the two lateral openings of the recess.A57. The patient interface assembly as in any one of clauses A1 to A56, wherein electrical wirings of the two or more electrical sensing elements of the electrical sensing arrangement are routed to the nasal interface.A58. The patient interface assembly as in clause A57, wherein the nasal interface comprises electrical connection points for the electrical wirings of the two or more electrical sensing elements.A59. The patient interface assembly as in clause A58 insofar as to be dependent on clause A44, wherein the at least one gases flow port and the electrical connection points are integrated together as a single connector for connecting to the gases flow delivery line and an electrical network for communication signals from the two or more electrical sensing elements.A60. The patient interface assembly as in clause A59 insofar as to be dependent on clause A45 or A46, wherein the electrical connection points are integrated with the delivery inlet of the gases delivery side member.A61 . The patient interface assembly as in clause A59 insofar as to be dependent on clause A51 , wherein the electrical connection points are integrated with the aperture in the upper portion of the face mount part.B1 . A patient interface assembly comprising: a headgear comprising a head strap portion for wearing around a back of a patient’s head; a nasal interface comprising a main portion, and at least one nasal delivery element extending from the main portion,wherein the nasal interface is held by the headgear to form a continuous loop; and an electrical sensing arrangement for detecting electrical activity of a patient to monitor a depth of anaesthesia of the patient, the electrical sensing arrangement comprising two or more electrical sensing elements distributed along the continuous loop.B2. The patient interface assembly as in clause B1 , wherein the main portion of the nasal interface is between a first lateral portion and a second lateral portion of the nasal interface, wherein the head strap portion of the headgear extends from the first lateral portion of the nasal interface to the second lateral portion of the nasal interface.B3. The patient interface assembly as in clause B1 or B2, wherein a distribution of the two or more electrical sensing elements from the first lateral portion of the nasal interface to a mid-point of the head strap portion is symmetrical with a distribution of the two or more electrical sensing elements from the second lateral portion of the nasal interface to the mid-point of the head strap portion.B4. The patient interface assembly as in any one of clauses B1 to B3, wherein each of the two or more electrical sensing elements is disposed along the continuous loop at a corresponding predetermined distance from a mid-point of the main portion of the nasal interface.B5. The patient interface assembly as in any one of clauses B1 to B4, wherein the continuous loop formed by the head strap portion of the headgear and the nasal interface is configured to loop across a top region of the patient’s head.B6. The patient interface assembly as in any one of clauses B1 to B5, wherein the head strap portion of the headgear is conformable to the patient’s head for wearing on the patient’s head, wherein, when the headgear is worn on the patient’s head, the nasal interface is retained to bear against a nose of the user along a first vector to maintain the nasal interface in a position and an orientation for delivering consistent gases flowinto the nose of the patient, and at least one of the two or more electrical sensing elements of the electrical sensing arrangement is retained to bear against a corresponding position of the patient’s head along a second vector to maximise contact with the corresponding position of the patient’s head.B7. The patient interface assembly as in clause B6 wherein the first vector forms an angle with a transverse plane of the patient’s head and is directed towards a coronal plane of the patient’s head, wherein the angle is between 0° and 90°.B8. The patient interface assembly as in clause B6 or B7, wherein the second vector is directed substantially perpendicular towards the corresponding position of the patient’s head.B9. The patient interface assembly as in any one of clauses B6 to B8, wherein the head strap portion of the headgear is resilient and is capable of returning to a contracted state for conforming the head strap portion of the headgear to the patient’s head after being widened to an expanded state.B10. The patient interface assembly as in any one of clauses B6 to B9, wherein the head strap portion of the headgear comprises elastic material stretchable to conform the head strap portion of the headgear to the patient’s head.B11 . The patient interface assembly as in any one of clauses B6 to B10, wherein the head strap portion of the headgear comprises an adjustable arrangement to tighten the head strap portion of the headgear for conforming to the patient’s head.B12. The patient interface assembly as in clause B11 , wherein the adjustable arrangement comprises one or more or a combination of a ring, a slide, a hook, a buckle, or a strap adjuster for adjusting the head strap portion of the headgear.B13. The patient interface assembly as in any one of clauses B1 to B12, wherein at least one of the two or more electrical sensing elements is fixedly attached to one or both of the head strap portion of the headgear and the nasal interface.B14. The patient interface assembly as in clause B13, wherein the at least one of the two or more electrical sensing elements is embedded in one or both of the head strap portion of the headgear and the nasal interface.B15. The patient interface assembly as in any one of clauses B1 to B12, wherein at least one of the two or more electrical sensing elements is movably attached to one or both of the head strap portion of the headgear and the nasal interface in a manner so as to be translatable between different positions thereof.B16. The patient interface assembly as in clause B15, wherein, when the at least one of the two or more electrical sensing elements is movably attached to the head strap portion of the headgear, the at least one of the two or more electrical sensing elements is attached to a slide attachment, the slide attachment comprising a slide channel through which the head strap portion of the headgear is fitted such that the slide attachment is slidable relative to the head strap portion of the headgear for moving said electrical sensing element along the head strap portion of the headgear.B17. The patient interface assembly as in clause B15 or B16, wherein the at least one of the two or more electrical sensing elements is removably attached thereto.B18. The patient interface assembly as in any one of clauses B1 to B12, wherein at least one of the two or more electrical sensing elements is removably attached to one or both of the head strap portion of the headgear and the nasal interface.C1 . A patient interface assembly for a patient’s head comprising: a headgear comprising a nasal strap portion for wearing over a nose bridge of the patient; a nasal interface comprising a main portion, and at least one nasal delivery element extending from the main portion, wherein the nasal interface is held by the headgear; and an electrical sensing arrangement for detecting electrical activity of the patient to monitor a depth of anaesthesia of the patient, the electrical sensing arrangementcomprising two or more electrical sensing elements distributed to one or both of the nasal strap portion of the headgear and the nasal interface.C2. The patient interface assembly as in clause C1 , wherein the main portion of the nasal interface is between a first lateral portion and a second lateral portion of the nasal interface, wherein the nasal strap portion of the headgear extends from the first lateral portion of the nasal interface to the second lateral portion of the nasal interface.C3. The patient interface assembly as in clause C1 or C2, wherein the nasal strap portion is of a predetermined length so as to maintain the nasal interface in place when worn.C4. The patient interface assembly as in any one of clauses C1 to C3, wherein the nasal strap portion is configured to apply a countering force to resist a load on one or more sides of the nasal interface.C5. The patient interface assembly as in any one of clauses C1 to C3, wherein at least one of the two or more electrical sensing elements of the electrical sensing arrangement is disposed at the nasal strap portion of the headgear.C6. The patient interface assembly as in clause C5, wherein a disposition of the at least one of the two or more electrical sensing elements and the nasal strap portion is configured to apply a countering force to resist a load on one or more sides of the nasal interface.C7. The patient interface assembly as in any one of clauses C1 to C6, wherein the nasal strap portion of the headgear is conformable to the nose bridge of the patient for wearing over the nose bridge of the patient, wherein, when the headgear is worn, the nasal interface is retained to bear against a nose of the patient along a first vector to maintain the nasal interface in a position and an orientation for delivering consistent gases flow into the nose of the patient, and at least one of the two or more electrical sensing elements of the electrical sensing arrangement is retained to bear against a corresponding positionof the nose bridge of the patient along a second vector to maximise contact with the corresponding position of nose bridge of the patient.C8. The patient interface assembly as in clause C7 wherein the first vector forms an angle with a transverse plane of the patient’s head and is directed towards a coronal plane of the patient’s head, wherein the angle is between 0° and 90°.C9. The patient interface assembly as in clause C7 or C8, wherein the second vector is directed substantially perpendicular towards the corresponding position of the nose bridge of the patient.C10. The patient interface assembly as in any one of clauses C7 to C9, wherein the nasal strap portion of the headgear is resilient and is capable of returning to a contracted state for conforming the nasal strap portion of the headgear to the nose bridge of the patient after being widened to an expanded state.C11 . The patient interface assembly as in any one of clauses C7 to C10, wherein the nasal strap portion of the headgear comprises elastic material stretchable to conform the nasal strap portion of the headgear to the nose bridge of the patient.C12. The patient interface assembly as in any one of clauses C7 to C11 , wherein the nasal strap portion of the headgear comprises an adjustable arrangement to tighten the nasal strap portion of the headgear for conforming to the nose bridge of the patient.C13. The patient interface assembly as in clause C12, wherein the adjustable arrangement comprises one or more or a combination of a ring, a slide, a hook, a buckle, or a strap adjuster for adjusting the nasal strap portion of the headgear.C14. The patient interface assembly as in any one of clauses C1 to C12, wherein at least one of the two or more electrical sensing elements is fixedly attached to one or both of the nasal strap portion of the headgear and the nasal interface.C15. The patient interface assembly as in clause C14, wherein the at least one of the two or more electrical sensing elements is embedded in one or both of the nasal strap portion of the headgear and the nasal interface.C16. The patient interface assembly as in any one of clauses C1 to C12, wherein at least one of the two or more electrical sensing elements is movably attached to one or both of the nasal strap portion of the headgear and the nasal interface in a manner so as to be translatable between different positions thereof.C17. The patient interface assembly as in clause C16, wherein, when the at least one of the two or more electrical sensing elements is movably attached to the nasal strap portion of the headgear, the at least one of the two or more electrical sensing elements is attached to a slide attachment, the slide attachment comprising a slide channel through which the nasal strap portion of the headgear is fitted such that the slide attachment is slidable relative to the nasal strap portion of the headgear for moving said electrical sensing element along the nasal strap portion of the headgear.C18. The patient interface assembly as in clause C16 or C17, wherein the at least one of the two or more electrical sensing elements is removably attached thereto.C19. The patient interface assembly as in any one of clauses C1 to C13, wherein at least one of the two or more electrical sensing elements is removably attached to one or both of the nasal strap portion of the headgear and the nasal interface.D1 . A patient interface assembly comprising: a nasal interface comprising a main portion between a first lateral portion and a second lateral portion, and at least one nasal delivery element extending from the main portion; and an electrical sensing arrangement for detecting electrical activity of a patient to monitor a depth of anaesthesia of the patient, the electrical sensing arrangement comprising two or more electrical sensing elements being disposed at the first lateral portion and / or the second lateral portion of the nasal interface.D2. The patient interface assembly as in clause D1 , comprising at least one electrical sensing element disposed at the first lateral portion of the nasal interface and at least one further electrical sensing element disposed at the second lateral portion of the nasal interface.D3. The patient interface assembly as in clause D1 , comprising two electrical sensing elements disposed side-by-side lengthwise at the first lateral portion of the nasal interface and / or two electrical sensing elements disposed side-by-side lengthwise at the second lateral portion of the nasal interface.D4. The patient interface assembly as in clause D1 , comprising two electrical sensing elements disposed at the first lateral portion of the nasal interface and side- by-side along a direction transverse to a length of the first lateral portion, and / or two electrical sensing elements disposed at the second lateral portion of the nasal interface and side-by-side along a direction transverse to a length of the second lateral portion.D5. The patient interface assembly as in any one of clauses D1 to D4, wherein each of the two or more electrical sensing elements is an electrode.D6. The patient interface assembly as in clause D5, wherein the electrode is an electroencephalography electrode.D7. The patient interface assembly as in any one of clauses D1 to D6, wherein each of the two or more electrical sensing elements is in the form of a cup, a disc, a patch, a pad or at least one needle.D8. The patient interface assembly as in any one of clauses D1 to D7, wherein at least one of the two or more electrical sensing elements comprises an adhesive surface or a frictional surface.D9. The patient interface assembly as in any one of clauses D1 to D8, wherein at least one of the two or more electrical sensing elements is fixedly attached to the nasal interface.D10. The patient interface assembly as in clause D9, wherein the at least one of the two or more electrical sensing elements is embedded in the nasal interface.D11 . The patient interface assembly as in any one of clauses D1 to D8, wherein at least one of the two or more electrical sensing elements is movably attached to the nasal interface in a manner so as to be translatable between different positions thereof.D12. The patient interface assembly as in clause D11 , wherein the at least one of the two or more electrical sensing elements is removably attached thereto.D13. The patient interface assembly as in any one of clauses D1 to D8, wherein at least one of the two or more electrical sensing elements is removably attached to the nasal interface.D14. The patient interface assembly as in any one of clauses D1 to D13, further comprising at least one non-electrical sensing element attached to the nasal interface, wherein the at least one non-electrical sensing element comprises one of a photosensing element, an optical sensing element, or a thermosensing element.D15. The patient interface assembly as in any one of clauses D1 to D14, wherein the at least one nasal delivery element is a nasal prong.D16. The patient interface assembly as in clause D15, wherein the nasal interface comprises two nasal prongs.D17. The patient interface assembly as in clause D16, wherein the two nasal prongs are of different dimensions.D18. The patient interface assembly as in clause D16, wherein the two nasal prongs are of a same dimension.D19. The patient interface assembly as in any one of clauses D1 to D18, wherein the nasal interface comprises at least one gases flow port disposed at one of (i) themain portion or (ii) the first lateral portion and / or the second lateral portion of the nasal interface, the at least one gases flow port being for receiving a gases flow, wherein the at least one gases flow port is in fluid communication with the at least one nasal delivery element.D20. The patient interface assembly as in clause D19, wherein, when the at least one gases flow port is disposed at the first lateral portion, the main portion comprises a manifold, the first lateral portion comprises a gases delivery side member extending from a corresponding side of the manifold, and the second lateral portion comprises a non-delivery side member extending from a corresponding opposite side of the manifold, wherein an end of the gases delivery side member distal from the manifold comprises a delivery inlet serving as the at least one gases flow port, wherein the at least one nasal delivery element extends from the manifold.D21 . The patient interface assembly as in clause D20, wherein when the at least one gases flow port is disposed at the second lateral portion, the main portion comprises a manifold, the second lateral portion comprises a gases delivery side member extending from a corresponding side of the manifold, and the first lateral portion comprises a non-delivery side member extending from a corresponding opposite side of the manifold, wherein an end of the gases delivery side member distal from the manifold comprises a delivery inlet serving as the at least one gases flow port, wherein the at least one nasal delivery element extends from the manifold.D22. The patient interface assembly as in clause D20 or D21 , wherein the gases delivery side member comprises a collapsible portion operable to change between a normally open configuration and a collapsed configuration.D23. The patient interface assembly as in clause D22, wherein the collapsible portion changes from the normally open configuration to the collapsed configuration upon application of a collapsing force to the collapsible portion.D24. The patient interface assembly as in any one of clauses D20 to D21 , further comprising a gas path connector connected to the delivery inlet.D25. The patient interface assembly as in clause D19, wherein, when the at least one gases flow port is disposed at the main portion, the at least one gases flow port is an opening in the main portion providing direct fluid access into a flow passage of the at least one nasal delivery element.D26. The patient interface assembly as in clause D25, wherein the nasal interface comprises a face mount part with an upper portion serving as the main portion from which the at least one nasal delivery element extends, and the at least one gases flow port is an aperture in the upper portion opening into the flow passage of the at least one nasal delivery element extending from the upper portion of the face mount part.D27. The patient interface assembly as in clause D26, wherein the face mount part comprises a face contacting portion, wherein upper portion and the face contacting portion are at an angle to one another.D28. The patient interface assembly as in clause D27, wherein the face mount part comprises an auxiliary portion extending from the upper portion to the face contacting portion to form a recess capable of receiving a gases flow manifold part.D29. The patient interface assembly as in clause D28, wherein the aperture in the upper portion is located along a segment of the upper portion forming the recess with the face contacting portion and the auxiliary portion.D30. The patient interface assembly as in clause D28 or D29, wherein the recess comprises two lateral openings for lateral insertion of the gases flow manifold part into the face mount part.D31 . The patient interface assembly as in clause D30, wherein the gases flow manifold part is at an end of a gas conduit, wherein an end of the gases flow manifold part distal from the gas conduit is closed and the gases flow manifold parthas an opening along a side of the gases flow manifold part, whereby the opening of the gases flow manifold part is capable of being aligned to the aperture of the upper portion of the face mount part when inserted into the face mount part via any one of the two lateral openings of the recess.D32. The patient interface assembly as in clause D1 to D31 , wherein the nasal interface comprises electrical connection points for the electrical wirings of the two or more electrical sensing elements.

Claims

Claims1 . A patient interface assembly for a patient’s head, comprising: a headgear; a nasal interface comprising a main portion between a first lateral portion and a second lateral portion, and at least one nasal delivery element extending from the main portion, wherein the nasal interface is retained by the headgear with the first lateral portion and the second lateral portion held by the headgear; and an electrical sensing arrangement for detecting electrical activity of the patient to monitor a depth of anaesthesia of the patient, the electrical sensing arrangement comprising two or more electrical sensing elements distributed to one or both of the headgear and the nasal interface.

2. The patient interface assembly as claimed in claim 1 , wherein each of the two or more electrical sensing elements is an electrode.

3. The patient interface assembly as claimed in claim 2, wherein the electrode is an electroencephalography electrode.

4. The patient interface assembly as claimed in any one of claims 1 to 3, wherein each of the two or more electrical sensing elements is in the form of a cup, a disc, a patch, a pad or at least one needle.

5. The patient interface assembly as claimed in any one of claims 1 to 4, wherein at least one of the two or more electrical sensing elements comprises an adhesive surface and / or a frictional surface.

6. The patient assembly as claimed in claim 5, wherein the adhesive surface and / or frictional surface comprises part of one or both of the headgear and the nasal interface.

7. The patient interface assembly as claimed in any one of claims 1 to 6, wherein the electrical sensing arrangement comprises three or more electrical sensing elements.

8. The patient interface assembly as claimed in any one of claims 1 to 7, wherein at least one of the two or more electrical sensing elements is fixedly attached to one or both of the headgear and the nasal interface.

9. The patient interface assembly as claimed in claim 8, wherein the at least one of the two or more electrical sensing elements is embedded in one or both of the headgear and the nasal interface.

10. The patient interface assembly as claimed in any one of claims 1 to 7, wherein at least one of the two or more electrical sensing elements is movably attached to one or both of the headgear and the nasal interface in a manner so as to be translatable between different positions thereof.11 . The patient interface assembly as claimed in claim 10, wherein, when the at least one of the two or more electrical sensing elements is movably attached to the headgear, the at least one of the two or more electrical sensing elements is attached to a slide attachment, the slide attachment comprising a slide channel through which a strap of the headgear is fitted such that the slide attachment is slidable relative to the strap of the headgear for moving said electrical sensing element along the strap of the headgear.

12. The patient interface assembly as claimed in any one of claims 1 to 7, 10 or11 , wherein at least one of the two or more electrical sensing elements is removably attached to one or both of the headgear and the nasal interface.

13. The patient interface assembly as claimed in any one of claims 1 to 12, wherein the headgear comprises a network of straps, wherein the network of straps comprises a pair of nodes respectively at two opposite lateral portions of the headgear corresponding to left and right portions of the headgear with the nasal interface being at an anterior position of the headgear.

14. The patient interface assembly as claimed in claim 13, wherein the network of straps comprises a first strap segment extending from a first node of the pair of nodes to the first lateral portion of the nasal interface and a second strap segment extending from a second node of the pair of nodes to the second lateral portion of the nasal interface.

15. The patient interface assembly as claimed in any one of claims 1 to 14, further comprising at least one non-electrical sensing element attached to one or both of the headgear and the nasal interface, wherein the at least one non-electrical sensing element comprises one of a photosensing element, an optical sensing element, or a thermosensing element.

16. The patient interface assembly as claimed in any one of claims 1 to 15, wherein the at least one nasal delivery element is a nasal prong.

17. The patient interface assembly as claimed in claim 16, wherein the nasal interface comprises two nasal prongs.

18. The patient interface assembly as claimed in claim 17, wherein the two nasal prongs are of different dimensions.

19. The patient interface assembly as claimed in claim 17, wherein the two nasal prongs are of a same dimension.

20. The patient interface assembly as claimed in any one of claims 1 to 19, wherein the headgear is conformable to the patient’s head for wearing on the patient’s head, wherein, when the headgear is worn on the patient’s head, the nasal interface is retained to bear against a nose of the patient along a first vector to maintain the nasal interface in a position and an orientation for delivering consistent gases flow into the nose of the patient, and at least one of the two or more electrical sensing elements of the electrical sensing arrangement is retained to bear against acorresponding position of the patient’s head along a second vector to maximise contact with the corresponding position of the patient’s head.21 . The patient interface assembly as claimed in claim 20 wherein the first vector forms an angle with a transverse plane of the patient’s head and is directed towards a coronal plane of the patient’s head, wherein the angle is between 0° and 90°.

22. The patient interface assembly as claimed in claim 20 or 21 , wherein the second vector is directed substantially perpendicular towards the corresponding position of the patient’s head.

23. The patient interface assembly as claimed in any one of claims 20 to 22, wherein the headgear is resilient and is capable of returning to a contracted state for conforming the headgear to the patient’s head after being widened to an expanded state.

24. The patient interface assembly as claimed in any one of claims 20 to 23, wherein the headgear comprises elastic material stretchable to conform the headgear to the patient’s head.

25. The patient interface assembly as claimed in any one of claims 20 to 24, wherein the headgear comprises an adjustable arrangement to tighten the headgear for conforming to the patient’s head.

26. The patient interface assembly as claimed in claim 25, wherein the adjustable arrangement comprises one or more or a combination of a ring, a slide, a hook, a buckle, or a strap adjuster for adjusting one or more straps of the headgear.

27. The patient interface assembly as claimed in any one of claims 1 to 26, wherein the headgear comprises a head strap portion that forms a continuous loop with the nasal interface.

28. The patient interface assembly as claimed in claim 27, wherein the head strap portion extends from the first lateral portion of the nasal interface to the second lateral portion of the nasal interface.

29. The patient interface assembly as claimed in claim 27 or 28, wherein the two or more electrical sensing elements of the electrical sensing arrangement are distributed along the continuous loop.

30. The patient interface assembly as claimed in any one of claims 27 to 29, wherein a distribution of the two or more electrical sensing elements from the first lateral portion of the nasal interface to a mid-point of the head strap portion is symmetrical with a distribution of the two or more electrical sensing elements from the second lateral portion of the nasal interface to the mid-point of the head strap portion.31 . The patient interface assembly as claimed in any one of claims 27 to 30, wherein each of the two or more electrical sensing elements is disposed along the continuous loop at a corresponding predetermined distance from a mid-point of the main portion of the nasal interface.

32. The patient interface assembly as claimed in any one of claims 27 to 31 , wherein the continuous loop formed by the head strap portion of the headgear and the nasal interface is configured to loop across a top region of the patient’s head.

33. The patient interface assembly as claimed in any one of claims 1 to 32, wherein the headgear comprises a nasal strap portion for wearing over a nose bridge of the patient.

34. The patient interface assembly as claimed in claim 33, wherein the nasal strap portion extends from the first lateral portion of the nasal interface to the second lateral portion of the nasal interface.

35. The patient interface assembly as claimed in claim 33 or 34, wherein the nasal strap portion is of a predetermined length so as to maintain the nasal interface in place when worn.

36. The patient interface assembly as claimed in any one of claims 33 to 35, wherein the nasal strap portion is configured to apply a countering force to resist a load on one or more sides of the nasal interface.

37. The patient interface assembly as claimed in any one of claims 33 to 35, wherein at least one of the two or more electrical sensing elements of the electrical sensing arrangement is disposed at the nasal strap portion of the headgear.

38. The patient interface assembly as claimed in claim 37, wherein a disposition of the at least one of the two or more electrical sensing elements and the nasal strap portion is configured to apply a countering force to resist a load on one or more sides of the nasal interface.

39. The patient interface assembly as claimed in any one of claims 1 to 38, wherein the headgear comprises a forehead strap portion for wearing across a forehead of the patient.

40. The patient interface assembly as claimed in claim 39, wherein at least one of the two or more electrical sensing elements of the electrical sensing arrangement is disposed at the forehead strap portion of the headgear.41 . The patient interface assembly as claimed in any one of claims 1 to 40, comprising at least one electrical sensing element disposed at the first lateral portion of the nasal interface and at least one further electrical sensing element disposed at the second lateral portion of the nasal interface.

42. The patient interface assembly as claimed in any one of claims 1 to 41 , comprising two electrical sensing elements disposed side-by-side lengthwise at the first lateral portion of the nasal interface and / or two electrical sensing elements disposed side-by-side lengthwise at the second lateral portion of the nasal interface.

43. The patient interface assembly as claimed in any one of claims 1 to 41 , comprising two electrical sensing elements disposed at the first lateral portion of the nasal interface and side-by-side along a direction transverse to a length of the first lateral portion, and / or two electrical sensing elements disposed in at the second lateral portion of the nasal interface and side-by-side along a direction transverse to a length of the second lateral portion.

44. The patient interface assembly as claimed in any one of claims 1 to 43, wherein the nasal interface comprises at least one gases flow port disposed at one of (i) the main portion or (ii) the first lateral portion and / or the second lateral portion of the nasal interface, the at least one gases flow port being for receiving a gases flow, wherein the at least one gases flow port is in fluid communication with the at least one nasal delivery element.

45. The patient interface assembly as claimed in claim 44, wherein, when the at least one gases flow port is disposed at the first lateral portion, the main portion comprises a manifold, the first lateral portion comprises a gases delivery side member extending from a corresponding side of the manifold, and the second lateral portion comprises a non-delivery side member extending from a corresponding opposite side of the manifold, wherein an end of the gases delivery side member distal from the manifold comprises a delivery inlet serving as the at least one gases flow port, wherein the at least one nasal delivery element extends from the manifold.

46. The patient interface assembly as claimed in claim 44, wherein when the at least one gases flow port is disposed at the second lateral portion, the main portion comprises a manifold, the second lateral portion comprises a gases delivery side member extending from a corresponding side of the manifold, and the first lateral portion comprises a non-delivery side member extending from a corresponding opposite side of the manifold, wherein an end of the gases delivery side member distal from the manifold comprises a delivery inlet serving as the at least one gases flow port, wherein the at least one nasal delivery element extends from the manifold.

47. The patient interface assembly as claimed in claim 45 or 46, wherein the gases delivery side member comprises a collapsible portion operable to change between a normally open configuration and a collapsed configuration.

48. The patient interface assembly as claimed in claim 47, wherein the collapsible portion changes from the normally open configuration to the collapsed configuration upon application of a collapsing force to the collapsible portion.

49. The patient interface assembly as claimed in any one of claims 45 to 48, further comprising a gas path connector connected to the delivery inlet.

50. The patient interface assembly as claimed in claim 44, wherein, when the at least one gases flow port is disposed at the main portion, the at least one gases flow port is an opening in the main portion providing direct fluid access into a flow passage of the at least one nasal delivery element.51 . The patient interface assembly as claimed in claim 50, wherein the nasal interface comprises a face mount part with an upper portion serving as the main portion from which the at least one nasal delivery element extends, and the at least one gases flow port is an aperture in the upper portion opening into the flow passage of the at least one nasal delivery element extending from the upper portion of the face mount part.

52. The patient interface assembly as claimed in claim 51 , wherein the face mount part comprises a face contacting portion, wherein upper portion and the face contacting portion are at an angle to one another.

53. The patient interface assembly as claimed in claim 52, wherein the face mount part comprises an auxiliary portion extending from the upper portion to the face contacting portion to form a recess capable of receiving a gases flow manifold part.

54. The patient interface assembly as claimed in claim 53, wherein the aperture in the upper portion is located along a segment of the upper portion forming the recess with the face contacting portion and the auxiliary portion.

55. The patient interface assembly as claimed in claim 53 or 54, wherein the recess comprises two lateral openings for lateral insertion of the gases flow manifold part into the face mount part.

56. The patient interface assembly as claimed in claim 55, wherein the gases flow manifold part is at an end of a gas conduit, wherein an end of the gases flow manifold part distal from the gas conduit is closed and the gases flow manifold part has an opening along a side of the gases flow manifold part, whereby the opening of the gases flow manifold part is capable of being aligned to the aperture of the upper portion of the face mount part when inserted into the face mount part via any one of the two lateral openings of the recess.

57. The patient interface assembly as claimed in any one of claims 1 to 56, wherein electrical wirings of the two or more electrical sensing elements of the electrical sensing arrangement are routed to the nasal interface.

58. The patient interface assembly as claimed in claim 57, wherein the nasal interface comprises electrical connection points for the electrical wirings of the two or more electrical sensing elements.

59. The patient interface assembly as claimed in claim 58 insofar as to be dependent on claim 44, wherein the at least one gases flow port and the electrical connection points are integrated together as a single connector for connecting to the gases flow delivery line and an electrical network for communication signals from the two or more electrical sensing elements.

60. The patient interface assembly as claimed in claim 59 insofar as to be dependent on claim 45 or 46, wherein the electrical connection points are integrated with the delivery inlet of the gases delivery side member.61 . The patient interface assembly as claimed in claim 59 insofar as to be dependent on claim 51 , wherein the electrical connection points are integrated with the aperture in the upper portion of the face mount part.

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